Ok Clinical Calculations Made Easy

APPROXIMATE EQUIVALENTS FOR METRIC, APOTHECARY, AND HOUSEHOLD WEIGHTS AND VOLUMES

CELSIUS AND FAHRENHEIT TEMPERATURE EQUIVALENTS

To convert from Fahrenheit to Celsius:ºC = (ºF − 32) ÷ 1.8

To convert from Celsius to Fahrenheit:ºF = ºC × 1.8 + 32

ºC = temperature in degrees CelsiusºF = temperature in degrees Fahrenheit

■■■■■■■■■■■■■■■■■■■■■■■■■■■■

APPROXIMATE EQUIVALENTS FOR WEIGHT

Metric Apothecary

1 kg (1000 g) 2.2 lb1 g (1000 mg) 15 gr60 mg 1 gr

APPROXIMATE EQUIVALENTS FOR VOLUME

Metric Apothecary Household

4000 mL 1 gal (4 qt)1 L (1000 mL) 1 qt (2 pt)500 mL 1 pt (16 fl oz)240 mL 8 oz 1 cup 30 mL 1 oz (8 dr) 2 tbsp15 mL 1⁄2 oz (4 dr) 1 tbsp (3 tsp)5 mL 1 dr (60 M) 1 tsp (60 gtt)1 mL 15 M 15 gtt

1 M 1 gtt

** Conversion Chart **Celsius to Fahrenheit35.0 95.035.5 95.936.0 96.836.5 97.737.0 98.637.5 99.538.0 100.438.5 101.339.0 102.239.5 103.140.0 104.040.5 104.941.0 105.841.5 106.742.0 107.6

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Clinical CalculationsMade EasySolving Problems Using Dimensional Analysis

Gloria P. Craig, EdD, MSN, RNProfessor

South Dakota State UniversityCollege of Nursing

Brookings, South Dakota

F I F T H E D I T I O N

LWBK732-FM_i-xii_NEW.qxd 11/27/10 2:28 PM Page iii

Senior Acquisitions Editor: Hilarie SurrenaProduct Manager: Eric Van Osten & Michelle ClarkeEditorial Assistant: Shawn LohtDirector of Nursing Production: Helen EwanSenior Designer: Joan WendtArt Director, Illustration: Brett MacNaughtonManufacturing Coordinator: Karin DuffieldCompositor: Aptara, Inc.

Fifth Edition

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Copyright © 2009, 2005, 2001 by Lippincott Williams & Wilkins. Copyright © 1997 by Lippincott-RavenPublishers. All rights reserved. This book is protected by copyright. No part of this book may be reproducedor transmitted in any form or by any means, including as photo copies or scanned-in or other electroniccopies, or utilized by any information storage and retrieval system without written permission from the copy-right owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in thisbook prepared by individuals as part of their official duties as U.S. government employees are not coveredby the above-mentioned copyright. To request permission, please contact Lippincott Williams & Wilkins atTwo Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at [email protected] orvia website at lww.com (products and services).

9 8 7 6 5 4 3 2 1

Printed in China

Library of Congress Cataloging-in-Publication Data

Craig, Gloria P., 1949-Clinical calculations made easy : solving problems using dimensional analysis / Gloria P. Craig. — 5th ed.

p. ; cm.Includes bibliographical references and index.ISBN 978-1-60831-790-5 (alk. paper)

1. Pharmaceutical arithmetic. 2. Dimensional analysis. 3. Nursing—Mathematics. I. Title. [DNLM: 1. Pharmaceutical Preparations—administration & dosage. 2. Mathematics. 3. Nurses’

Instruction. 4. Problem Solving. 5. Problems and Exercises. QV 748 C886ca 2009]RS57.C73 2009615�.14—dc22 2007042536

Care has been taken to confirm the accuracy of the information presented and to describe generally acceptedpractices. However, the authors, editors, and publisher are not responsible for errors or omissions or for anyconsequences from application of the information in this book and make no warranty, expressed or implied,with respect to the currency, completeness, or accuracy of the contents of the publication. Application of thisinformation in a particular situation remains the professional responsibility of the practitioner; the clinicaltreatments described and recommended may not be considered absolute and universal recommendations.

The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosageset forth in this text are in accordance with the current recommendations and practice at the time of publi-cation. However, in view of ongoing research, changes in government regulations, and the constant flow ofinformation relating to drug therapy and drug reactions, the reader is urged to check the package insert foreach drug for any change in indications and dosage and for added warnings and precautions. This is partic-ularly important when the recommended agent is a new or infrequently employed drug.

Some drugs and medical devices presented in this publication have Food and Drug Administration(FDA) clearance for limited use in restricted research settings. It is the responsibility of the health careprovider to ascertain the FDA status of each drug or device planned for use in his or her clinical practice.

LWW.COM

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mailto:[email protected]

lww.com

LWW.COM

Teresa Aprigliano, EdD, RNAssociate Professor, Director

Molloy CollegeRockville Centre, New York

Patricia Ann Dudley, MSN, RN, CRNPNursing Faculty

University of Alabama at BirminghamBirmingham, Alabama

Sharon Koval Falkenstern, PhD, CRNP, PNP-CInstructor, Family Nurse Practitioner Program Coordinator

Pennsylvania State UniversityUniversity Park, Pennsylvania

Barbara J. Hoerst, PhD, RNAssistant ProfessorLa Salle University

Philadelphia, Pennsylvania

Cathy Malone, MSN, BSN, RNAssistant Professor

University of North AlabamaFlorence, Alabama

Anna Sanford, MSN, APRN, BCAssociate Professor

Northern Michigan UniversityMarquette, Michigan

Cynthia L. Terry, MSN, RN, CCRNProfessor

Lehigh Carbon Community CollegeSchnecksville, Pennsylvania

Ina E. Warboys, MS, RNClinical Assistant Professor

University of Alabama in HuntsvilleHuntsville, Alabama

Reviewers

v

LWBK732-FM_i-xii_NEW.qxd 11/27/10 2:28 PM Page v

Loretta L. White, DNS, RNAssistant Professor

Indiana State UniversityTerre Haute, Indiana

Rosemary Wittstadt, EdD, RNAdjunct Professor

Howard Community CollegeColumbia, Maryland

v i REVIEWERS

LWBK732-FM_i-xii_NEW.qxd 11/27/10 2:28 PM Page vi

v i i

Many people experience stumbling blocks calculat-ing math problems because of a lack of mathe-

matical ability or associated “math anxiety.” Even peoplewith strong math skills often set up medication prob-lems incorrectly, putting the patient at an increased riskfor incorrect dosages and the ensuing consequences.However, dosage calculation need not be difficult if youuse a problem-solving method that is easy to understandand to implement.

As a student, I experienced anxiety related to poormathematical abilities and consequently had difficultywith medication calculations. However, a friend intro-duced me to a problem-solving method that was easyto visualize. By using this method, I was able to easilyunderstand medication problems and thereby avoidthe stumbling blocks that I had experienced withother methods of dosage calculations. Later, as a prac-ticing nurse and nursing instructor, I realized thatmany of my colleagues and students shared my expe-rience with “math anxiety,” so I began sharing thisproblem-solving method with them.

During my baccalaureate nursing education, thisproblem-solving method became my teaching plan.During my master’s education, it became my research.During my doctoral education, it became my disser-tation. Now, I would like to share this method withanyone who ever believed that they were mathemati-cally “challenged” or trembled at the thought of solv-ing a medication problem.

The method, called dimensional analysis (alsoknown as factor-label method or conversion-factormethod), is a systematic, straightforward approach tosetting up and solving problems that require conver-sions. It is a way of thinking about problems that canbe used when two quantities are directly proportionalto each other, but one needs to be converted using aconversion factor in order for the problem to besolved.

Preface

Dimensional Analysis as aTeaching ToolDimensional analysis empowers the learner to solve avariety of medication problems using just one prob-lem-solving method. Research has shown that studentsexperience less frustration and create fewer medicationerrors if one problem-solving method is used to solveall medication problems. As a method of reducingerrors and improving calculation abilities, dimensionalanalysis has many possibilities. Whether it is used inpractice or education, it is a strong approach when thegoals are improving medication dosage-calculationskills, reducing medication errors, and improvingpatient safety. Ultimately, this improved methodologyhas the potential to reduce the medication errors thatoccur within the discipline of nursing.

Dimensional analysis helps the learner see andunderstand the significance of the whole process,since it focuses on how to learn, rather than what tolearn. It provides a framework for understanding theprinciples of the problem-solving method and sup-ports the critical thinking process. It helps the learnerto organize and evaluate data, and to avoid errors insetting up problems. Dimensional analysis thus sup-ports the conceptual mastery and higher-level think-ing skills that have become the core of curricula at alllevels of nursing education.

Organization of the TextThis text uses the simple-to-complex approach inteaching students clinical calculations and is, there-fore, divided into four sections.

Section 1: Clinical CalculationsChapter 1 provides an arithmetic pretest to help

gauge the amount of time a student will need to spend reviewing the basic arithmetic skillspresented in this chapter.

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Chapter 2 reviews systems of measurement, commonequivalents, calculating patient intake and output,and converting standard time and military time.

Chapter 3 introduces the student to dimensionalanalysis and uses common equivalents to helpthe student practice problem solving with thisnew method.

Chapter 4 builds on the previous chapter by intro-ducing one-factor conversions.

Chapter 5 continues the growth process by presenting two-factor con versions.

Chapter 6 completes the student’s understandingof clinical calculations by introducing three-factor conversions.

Section 2: Practice ProblemsSection 2 allows the student the opportunity to refinethe skills presented in section 1 by providing addi-tional one-, two-, and three-factor practice problemsfollowed by comprehensive questions to ensure accu-rate understanding of clinical calculations.

Section 3: Case StudiesSection 3 helps the student relate dosage calculationsto real clinical situations. Thirty-five case studies thatare related to different fields of nursing are includedin this section.

Section 4: Comprehensive Post-TestSection 4 contains a post-test of 20 questions allowingthe instructor to assess the student’s mastery of solv-ing clinical calculations using dimensional analysis.The answers to these questions as well as additionalpost-tests are available to instructors on .

Special FeaturesEach chapter in Section 1 contains numerous Exampleswith detailed explanations. Thinking It Throughprovides additional explanations to help studentsmore fully understand complex topics. In-chapterExercises occur after the presentation and explana-tion of each new concept, providing an opportunityfor the student to gain ability and confidence in thematerial before proceeding to the next concept. Addi-tional Practice Problems are provided at the end ofthe chapter so that students can practice the skills andassess areas where more review may be necessary. AnAnswer Key for all Exercises and Practice Problems isalso located at the end of each chapter. Additionally,a Post-Test, designed so that students can tear it outof the book and hand it in to their instructor, appearsat the end of each chapter. Additional Post-Tests andanswers are available to instructors on .

In addition:

● Actual drug labels are liberally used throughoutthe text to provide the student with clinically real-istic examples.

● A special feature, Preventing Med-ication Errors, helps identify keyconcepts necessary for avoiding clini-cal calculation errors.

● A special icon identifying pediatricmedication problems allows stu-dents and teachers to quickly find allpediatric problems in the text.

New to This EditionThe fifth edition provides many more opportunitiesfor students to practice their skills. More problemshave been added throughout the text and all problemshave been updated to follow guidelines from theInstitute for Safe Medication Practices. Calculationof intake and output and converting standard timeand military time are included to aid students inlearning accurate medical recording. Ten new casestudies including pediatric problems have also beenadded as well as a new Comprehensive Post-Test.

Resources on (http://thepoint.lww.com), a trademark of

Wolters Kluwer Health, is a web-based course andcontent management system providing every resourcethat instructors and students need in one easy-to-usesite. Advanced technology and superior content com-bine at thePoint to allow instructors to design anddeliver on-line and off-line courses, maintain gradesand class rosters, and communicate with students.

Instructors will also find

● Additional Post-Tests Answer keys● Instructor’s Manual● PowerPoint presentations

Students can visit thePoint to access supplementalmultimedia resources to enhance their learning expe-rience, download content, upload assignments, andjoin an on-line study group.

Also available to students are

● Additional practice problems ● Additional post-tests

By using this text and all of its resources, it is my hopethat this fifth edition will help students find that clinical calculation can indeed be made easy usingdimensional analysis.

v i i i PREFACE

GLORIA P. CRAIG

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http://thepoint.lww.com

There are many people who have assisted me with my professional growth anddevelopment, including:

Pauline Callahan, who believed that I would be a great nurse and nursinginstructor when I could not believe in myself.

Jackie Kehm, who introduced me to dimensional analysis and helped me pass themedication module that I was sure would be my stumbling block.

Dr. Sandra L. Sellers, for her expertise and guidance throughout the process ofwriting my thesis and dissertation and her encouragement to write a textbook.

Margaret Cooper, for her friendship and editing support throughout the writingof this textbook.

My students, colleagues, and reviewers, for helping me develop my abilities toexplain and teach the problem-solving method of dimensional analysis.

The numerous pharmaceutical companies listed throughout this book that suppliedmedication labels and gave permission for the labels to be included in this textbook.

The faculty at South Dakota State University, College of Nursing, for allowingdimensional analysis to be integrated into the curriculum as the problem-solvingmethod for medication calculation.

The Lippincott editorial and production teams, for all of their hard work: HilarieSurrena, Senior Acquisitions Editor; Eric Van Osten and Michelle Clarke, ProductManagers; and Joan Wendt, Design Coordinator.

To these people and many more, I would like to express my sincere appreciationfor their mentoring, guidance, support, and encouragement that have helped toturn a dream into a reality.

This fifth edition of my text is dedicated to my children, Lori (and her husband,Michael) and Randy (and his wife Samantha), and to my granddaughters, Zoë,Ava, and Lily.

Acknowledgments

i x

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Contents

S E C T I O N 1Clinical Calculations 1

ARITHMETIC REVIEW 3C H A P T E R 1Arithmetic Review 5Arabic Numbers and Roman Numerals 6

Exercise 1.1 Arabic Numbers and Roman Numerals 7

Fractions 9Multiplying Fractions 9

Exercise 1.2 Multiplying Fractions 10

Dividing Fractions 11

Exercise 1.3 Dividing Fractions 12

Decimals 12

Rounding Decimals 13

Exercise 1.4 Rounding Decimals 13

Multiplying Decimals 14

Exercise 1.5 Multiplying Decimals 14

Dividing Decimals 15

Exercise 1.6 Dividing Decimals 15

Converting Fractions to Decimals 16

Exercise 1.7 Converting Fractions to Decimals 16

Practice Problems 18

Post-Test 21

Answer Key 23

C H A P T E R 2Systems of Measurement and Common Equivalents 31Systems of Measurement 32

The Metric System 32

The Apothecaries’ System 33

The Household System 33

Intake and Output 35Temperature 35

Time 36

Common Equivalents 37Practice Problems 40

Post-Test 43

Answer Key 45

C H A P T E R 3Solving Problems Using Dimensional Analysis 47Terms Used in Dimensional Analysis 48The Five Steps of Dimensional Analysis 48

Exercise 3.1 Dimensional Analysis 52


Post-Test 59

Answer Key 61

C H A P T E R 4One-Factor Medication Problems 67Interpretation of Medication Orders 68

Right Patient 68

Right Drug 68

Right Dosage 69

Right Route 69

Right Time 69

Right Documentation 69

Exercise 4.1 Interpretation of Medication Orders 70

Medication Administration Record 70

Exercise 4.2 Medication Administration Record 71

One-Factor Medication Problems 72

Principles of Rounding 75Exercise 4.3 One-Factor Medication Problems 78

Components of a Drug Label 78Identifying the Components 78

Exercise 4.4 Identifying the Components of

Drug Labels 79

Solving Problems With Components of Drug Labels 81

Exercise 4.5 Problems With Components of

Drug Labels 83

x

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Administering Medication by Different Routes 84Enteral Medications 84

Exercise 4.6 Administering Enteral Medications 89

Parenteral Medications 90

Exercise 4.7 Administering Parenteral Medications 95


Post-Test 103

Answer Key 109

C H A P T E R 5Two-Factor Medication Problems 114Medication Problems Involving Weight 115

Exercise 5.1 Pediatric Medication Problems Involving

Weight 117

Medication Problems Involving Reconstitution 119Exercise 5.2 Medication Problems Involving

Reconstitution 123

Medication Problems Involving Intravenous Pumps 124

Exercise 5.3 Medication Problems Involving Intravenous

Pumps 127

Medication Problems Involving Drop Factors 128Exercise 5.4 Medication Problems Involving

Drop Factors 132

Medication Problems Involving Intermittent Infusion 132

Exercise 5.5 Medication Problems Involving Intermittent

Infusion 134


Post-Test 141

Answer Key 147

C H A P T E R 6Three-Factor Medication Problems 151

Exercise 6.1 Medication Problems Involving Dosage,

Weight, and Time 158


Post-Test 169

Answer Key 175

S E C T I O N 2Practice Problems 179

One-Factor Practice Problems 179

Two-Factor Practice Problems 193

Three-Factor Practice Problems 204

Comprehensive Practice Problems 210

Answer Key 215

S E C T I O N 3Case Studies 229

Case Study 1 Congestive Heart Failure 229

Case Study 2 COPD/Emphysema 230

Case Study 3 Small Cell Lung Cancer 231

Case Study 4 Acquired Immunodeficiency Syndrome (AIDS) 231

Case Study 5 Sickle Cell Anemia 232

Case Study 6 Deep Vein Thrombosis 233

Case Study 7 Bone Marrow Transplant 234

Case Study 8 Pneumonia 235

Case Study 9 Pain 235

Case Study 10 Cirrhosis 236

Case Study 11 Hyperemesis Gravidarum 237

Case Study 12 Preeclampsia 238

Case Study 13 Premature Labor 238

Case Study 14 Cystic Fibrosis 239

Case Study 15 Respiratory Syncytial Virus (RSV) 240

Case Study 16 Leukemia 241

Case Study 17 Sepsis 242

Case Study 18 Bronchopulmonary Dysplasia 243

Case Study 19 Cerebral Palsy 244

Case Study 20 Hyperbilirubinemia 245

Case Study 21 Spontaneous Abortion 245

Case Study 22 Bipolar Disorder 246

Case Study 23 Anorexia Nervosa 247

Case Study 24 Clinical Depression 248

Case Study 25 Alzheimer’s Disease 249

Case Study 26 Otitis Media 249

Case Study 27 Seizures 250

Case Study 28 Fever of Unknown Origin 251

Case Study 29 TURP with CBI 252

Case Study 30 Hypercholesterolemia 252

Case Study 31 Hypertension 253

Case Study 32 Diabetic Ketoacidosis 254

Case Study 33 End-Stage Renal Failure 255

Case Study 34 Fluid Volume Deficit 256

Case Study 35 Increased Intracranial Pressure 256

Case Study 36 Breast Cancer 257

CONTENTS x i

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Case Study 37 Severe Abdominal Pain 258

Case Study 38 Acute Asthma Attack 259

Case Study 39 Right Total Hip Replacement 260

Case Study 40 Colon Resection 260

Case Study 41 Left Total Knee Replacement 261

Case Study 42 Chest Pain 262

Case Study 43 Pneumococcal Meningitis 263

Case Study 44 Diabetic Ketoacidosis 264

Case Study 45 C-Section Delivery 264

Answer Key 267

S E C T I O N 4Comprehensive Post-Test 281

AppendixEducational Theory of Dimensional Analysis 287

Index 289

x i i CONTENTS

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Clinical Calculations

S E C T I O N 1

LWBK732_c01_p1-30_LWBK732 11/26/10 9:20 PM Page 1

CHAPTER 1 Arithmetic Review 3

Chapter 1 Pre-Test Arithmetic Review

Name Date

Converting Between Arabic Numbers and Roman Numerals

1. 7 � __________

2. XI � __________

3. 17 � __________

4. XVI � __________

Multiplying and Dividing Fractions

5.

6.

7.

8.

9.

10.

Converting Fractions to Decimals

11.

12.

13.

14.

Multiplying and Dividing Decimals

15. 2.75 × 1.25 �

16. 0.25 ÷ 0.4 �

17. 4.50 × 0.75 �

18. 10.50 ÷ 4.5 �

19. 1.2 × 2 �

20. 1.5 ÷ 0.75 �

2

8

2

2× =

2

5

1

10÷ =

2

6

1

2× =

1

3

3

9÷ =

3

4

2

3× =

2

4

1

2÷ =

4

8=

2

6=

5

9=

1

4=


Arithmetic Review

Objectives

After completing this chapter, you will success-fully be able to:

1. Express Arabic numbers as Roman numerals.2. Express Roman numerals as Arabic numbers.3. Identify the numerator and denominator in a

fraction.4. Multiply and divide fractions.5. Multiply and divide decimals.6. Convert fractions to decimals.

Every nurse must know and practice the six rights ofmedication administration including the

1. Right drug2. Right dose3. Right route4. Right time5. Right patient6. Right documentation

Although the right drug, route, time, patient, and documentation may be readilyidentified, the right dose requires arithmetic skills that may be difficult for you. Thischapter reviews the basic arithmetic skills (multiplication and division) necessary for calculating medication dosage problems using the problem-solving method of dimen-sional analysis. Calculating the right dose of medication to be administered to apatient is one of the first steps toward preventing medication errors.

Outline

ARABIC NUMBERS AND ROMAN NUMERALS 6Exercise 1.1: Arabic Numbers and Roman Numerals 7

FRACTIONS 9Multiplying Fractions 9Exercise 1.2: Multiplying Fractions 10

Dividing Fractions 11Exercise 1.3: Dividing Fractions 12

DECIMALS 12Rounding Decimals 13Exercise 1.4: Rounding Decimals 13

Multiplying Decimals 14Exercise 1.5: Multiplying Decimals 14

Dividing Decimals 15Exercise 1.6: Dividing Decimals 15

CONVERTING FRACTIONS TO DECIMALS 16Exercise 1.7: Converting Fractions to Decimals 16

Practice Problems for Chapter 1: Arithmetic Review 18Post-Test for Chapter 1: Arithmetic Review 21Answer Key for Chapter 1: Arithmetic Review 23

5

PREVENTINGMEDICATIONERRORS

C H A P T E R 1


6 S E C T I O N 1 Clinical Calculations


Correctly identifyingRoman numerals will assistin preventing medicationerrors. Some medicationorders may include aRoman numeral.

Example: Administer X grof aspirin, which is correctlyinterpreted as administer 10 gr of aspirin.

However, according tothe Institute for Safe Med-ication Practices (ISMP),abbreviations increase therisk of medication errors.Additionally, while somehealth care providers maystill use roman numeralsand the apothecaries’ sys-tem, the ISMP recommendsusing the metric system.

ARABIC NUMBERS AND ROMAN NUMERALS

Most medication dosages are ordered by the physician or the nurse practitioner inthe metric and household systems for weights and measures using the Arabic num-ber system with symbols called digits (ie, 1, 2, 3, 4, 5). Occasionally, orders arereceived in the apothecaries’ system of weights and measures using the Romannumeral system with numbers represented by symbols (ie, I, V, X). The Romannumeral system uses seven basic symbols, and various combinations of these symbolsrepresent all numbers in the Arabic number system.

Table 1.1 includes the seven basic Roman numerals and the correspondingArabic numbers.

The combination of Roman numeral symbols is based on three specific principles:

1. Symbols are used to construct a number, but no symbol may be used morethan three times. The exception is the symbol for five (V), which is used onlyonce because there is a symbol for 10 (X) and a combination of symbols for15 (XV).

E X A M P L E 1 . 1

III � (1 � 1 � 1) � 3XXX � (10 � 10 � 10) � 30

E X A M P L E 1 . 2

VIII � (5 � 3) � 8XVII � (10 � 5 � 1 � 1) � 17

E X A M P L E 1 . 3

IV � (5 � 1) � 4IX � (10 � 1) � 9

2. When symbols of lesser value follow symbols of greater value, they are added toconstruct a number.

3. When symbols of greater value follow symbols of lesser value, those of less ervalue are subtracted from those of higher value to construct a number.

TABLE 1.1 Seven Basic Roman Numerals

I 1V 5X 10L 50C 100D 500M 1000

Roman Numerals Arabic Numbers



Exercise 1.1 Arabic Numbers and Roman Numerals

(See page 23 for answers)

Express the following Arabic numbers as Roman numerals.

1. 1 �

2. 2 �

3. 3 �

4. 4 �

5. 5 �

6. 6 �

7. 7 �

8. 8 �

9. 9 �

10. 10 �

11. 11 �

12. 12 �

13. 13 �

14. 14 �

15. 15 �

16. 16 �

17. 17 �

18. 18 �

19. 19 �

20. 20 �

Although medication orders rarely involve Roman numerals higher than 20, foradditional practice, express the following Arabic numbers as Roman numerals.

21. 43 �

22. 24 �

23. 55 �

24. 32 �

25. 102 �

26. 150 �

27. 75 �

(Exercise continues on page 8)


8 S E C T I O N 1 Clinical Calculations

28. 92 �

29. 64 �

30. 69 �

Express the following Roman numerals as Arabic numbers.

31. II �

32. IV �

33. VI �

34. X �

35. VIII �

36. XIX �

37. XX �

38. XVIII �

39. I �

40. XV �

41. III �

42. V �

43. IX �

44. VII �

45. XI �

46. XIV �

47. XVI �

48. XII �

49. XVII �

50. XIII �

To increase your abilities to use either system, convert the following Arabic num-bers or Roman numerals.

51. 19 �

52. XII �

53. 7 �

54. IX �

55. IV �

56. 11 �

57. VIII �



58. 16 �

59. XX �

60. 5 �

61. I �

62. 18 �

63. VI �

64. 2 �

65. III �

66. 10 �

67. XIII �

68. 14 �

69. XV �

70. 17 �

FRACTIONS

Medication dosages with fractions are occasionally ordered by the physician or usedby the pharmaceutical manufacturer on the drug label. A fraction is a number thatrepresents part of a whole number and contains three parts:

1. Numerator—the number on the top portion of the fraction that represents thenumber of parts of the whole fraction.

2. Dividing line—the line separating the top portion of the fraction from the bottom portion of the fraction.

3. Denominator—the number on the bottom portion of the fraction that represents the number of parts into which the whole is divided.

To solve medication dosage calculation problems using dimensional analy-sis, you must be able to identify the numerator and denominator portion of theproblem. You also must be able to multiply and divide numbers, fractions, anddecimals.

Multiplying FractionsThe three steps for multiplying fractions are:

1. Multiply the numerators.2. Multiply the denominators.3. Reduce the product to the lowest possible fraction.

3

4= numerator

denominator


Understanding fractionswill assist in preventingmedication errors. A med-ication order may include afraction.

Example: Administer1/150 gr of nitroglycerin.


1 0 S E C T I O N 1 Clinical Calculations

E X A M P L E 1 . 4

24

18

× = =

( )( ) ×

2

numeratordenominator

nume

321

16

24

1

or

rratordenominator

numeratordenominato

( )( ) =

( )8

232 rr

reduced to lowest possible fraction

( )

= ( )116

E X A M P L E 1 . 5

12

24

28

14

12

2

× = =

( )( ) ×

or


numerattordenominator


( )( ) =

( )( )4

28

== ( )14

reduced to lowest possible fraction

Exercise 1.2 Multiplying Fractions

(See pages 23–24 for answers)

To increase your abilities when working with fractions, multiply the following frac-tions and reduce to the lowest fractional term.

1.

2.

3.

4.

5.

6.

3

4

5

8× =

1

3

4

9× =

2

3

4

5× =

3

4

1

2× =

1

8

4

5× =

2

3

5

8× =


Dividing FractionsThe four steps for dividing fractions are:

1. Invert (turn upside down) the divisor portion of the problem (the second fractionin the problem).

2. Multiply the two numerators.3. Multiply the two denominators.4. Reduce answer to lowest term (fraction or whole number).

CHAPTER 1 Arithmetic Review 1 1

7.

8.

9.

10.

3

8

2

3× =

4

7

2

4× =

4

5

1

2× =

1

4

1

8× =

E X A M P L E 1 . 6

24

18

24

81

164

4

24

1

÷ = × = =

( )( ) ÷

or


nnumeratordenominator

numerator nu

( )( )

=( ) ×

8

2 8 mmeratorinverted fraction

denominator( )( )

=( ) ×

164 11 4

4

denominator

answer reduced to lowest ter

( ) =

= mm( )

E X A M P L E 1 . 7

12

24

12

42

44

1

12

2

÷ = × = =

( )( ) ÷

or


nuumeratordenominator

numerator numerat

( )( )

=( ) ×

4

1 4 oorinverted fraction

denominator denom( )( )

=( )×

42 2 iinator

answer reduced to lowest term

( ) =

= ( )4

1


DECIMALS

Medication orders are often written using decimals, and pharmaceutical manufac-turers may use decimals when labeling medications. Therefore, you must under-stand the learning principles involving decimals and be able to multiply and dividedecimals.

● A decimal point is preceded by a zero if not preceded by a number to decreasethe chance of an error if the decimal point is missed.


Exercise 1.3 Dividing Fractions


To increase your abilities when working with fractions, divide the following frac-tions and reduce to the lowest fractional term.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

3

4

2

3÷ =

1

9

3

9÷ =

2

3

1

6÷ =

1

5

4

5÷ =

3

6

4

8÷ =

5

8

5

8÷ =

1

8

2

3÷ =

1

5

1

2÷ =

1

4

1

2÷ =

1

6

1

3÷ =

E X A M P L E 1 . 8

0.25


● A decimal point may be preceded by a number and followed by a number.

● Numbers to the left of the decimal point are units, tens, hundreds, thousands, andten-thousands.

● Numbers to the right of the decimal point are tenths, hundredths, thousandths,and ten-thousandths.

Rounding Decimals● Decimals may be rounded off. If the number to the right of the decimal is

greater than or equal to 5, round up to the next number.● If the number to the right of the decimal is less than 5, delete the remaining

numbers.


Exercise 1.4 Rounding Decimals


Practice rounding off the following decimals to the tenth.

1. 0.75 �

2. 0.88 �

3. 0.44 �

4. 0.23 �

5. 0.67 �

6. 0.27 �

7. 0.98 �

8. 0.92 �

9. 0.64 �

10. 0.250 �

E X A M P L E 1 . 9

1.25

E X A M P L E 1 . 1 0

0.2 � 2 tenths0.05 � 5 hundredths0.25 � 25 hundredths1.25 � 1 unit and 25 hundredths

110.25 � 110 units and 25 hundredths

E X A M P L E 1 . 1 1

0.78 � 0.80.213 � 0.2


Understanding the impor-tance of a decimal pointwill assist in preventingmedication errors. Animproper placement of adecimal point can result ina serious medication error.According to the Institutefor Safe Medication Prac-tices (ISMP):

Trailing zeros should notbe used with whole numbers.

Example: Administer 1 mgof Xanax.

If a decimal point and azero are placed after thenumber (1.0 mg), theorder could be misread asAdminister 10 mg ofXanax.

Leading zeros shouldalways precede a decimalpoint when the dosage is nota whole number.

Example: Administer0.125 mg of Lanoxin.

If a zero is not placed infront of the decimal pointthe order could be misreadas Administer 125 mg ofLanoxin.


Multiplying DecimalsWhen multiplying with decimals, the principles of multiplication still apply. Thenumbers are multiplied in columns, but the number of decimal points are countedand placed in the answer, counting places from right to left.


E X A M P L E 1 . 1 2

2 3 11 5 1..

( decimal point)( decimal point)

115230

×

3 45.

Exercise 1.5 Multiplying Decimals


Practice multiplying the following decimals.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

2 54 6

.

.×

1 450 25

.

.×

3 90 8

..×

2 560 45

..×

10 650 05..×

1 983 10..×

2 755 0..×

5 00 45..×

7 500 25..×

2 50 01..×

Thin kingit

ThroughThe answer to the problembefore adding decimal pointsis 345 but when decimalpoints are correctly added(two decimal points areadded to the answer, count-ing two places from theright to the left) then 3.45becomes the correctanswer.

LWBK732_c01_p1-30:LWBK732 12/6/10 4:16 PM Page 14

Dividing DecimalsWhen dividing with decimals, the principles of division still apply, except that thedividing number is changed to a whole number by moving the decimal point to theright. The number being divided also changes by accepting the same number ofdecimal point moves.


Exercise 1.6 Dividing Decimals


Practice dividing the following decimals and rounding the answers to the tenth.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

)3 4 9 6. .

)0 25 12 50. .

)0 56 18 65. .

)0 3 0 192. .

)0 4 12 43. .

)0 5 12 50. .

)0 125 0 25. .

)0 08 0 085. .

)1 5 22 5. .

)5 5 16 5. .

E X A M P L E 1 . 1 3

Step 1 Move decimal point one place to the right.

Step 2

1.5

)0 5 0 75. .

)5 7 552525

0

1 5..



CONVERTING FRACTIONS TO DECIMALS

When problem solving with dimensional analysis, medication dosage calculationproblems may frequently contain both fractions and decimals. Some of you mayhave fraction phobia and prefer to convert fractions to decimals when solving prob-lems. To convert a fraction to a decimal, divide the numerator portion of the frac-tion by the denominator portion of the fraction.

When dividing fractions, remember to add a decimal point and a zero if thenumerator cannot be divided by the denominator.

E X A M P L E 1 . 1 4

)12

12 1 0

1 0

0 5or

(numerator)2 (denominator)

==

.

. 00 5.

E X A M P L E 1 . 1 5E X A M P L E 1 . 1 5

34

34 3 00

2 8or

(numerator)4 (denominator)

= .)22020

0 75 0 75. .=

Exercise 1.7 Converting Fractions to Decimals


To decrease fraction phobia, practice converting the following fractions to deci-mals. Remember to follow the rules of rounding.

1.

2.

3.

4.

5.

6.

1

8=

1

4=

2

5=

3

5=

2

3=

6

8=


Understanding the impor-tance of converting frac-tions to decimals willassist in preventing med-ication errors. Many med-ication errors occurbecause of a simple arith-metic error with dividing.Every nurse should have a calculator to recheckanswers for accuracy. If arecheck results in a differ-ent answer, the nextrecheck should includeconsulting with anothernurse or pharmacist.



7.

8.

9.

10.

3

8=

1

3=

3

6=

2

10=



Summary

This chapter has reviewed basic arithmetic that will assist you to successfully imple-ment dimensional analysis as a problem-solving method for medication dosage cal-culations. To assess your understanding and retention, complete the followingpractice problems.

Practice Problems for Chapter 1 Arithmetic Review


Change the following Arabic numbers to Roman numerals.

1. 2 �

2. 4 �

3. 5 �

4. 14 �

5. 19 �

6. 16 �

Change the following Roman numerals to Arabic numbers.

7. VI �

8. IX �

9. XII �

10. XVII �

11. XIX �

12. XXV �

Multiply the following fractions and reduce the answer to the lowest fractional term.

13.

14.

15.

16.

17.

18.

3

4

2

5× =

2

3

5

8× =

1

2

2

3× =

4

5

2

7× =

7

8

1

3× =

1

8

1

8× =


Divide the following fractions and reduce the answer to the lowest fractional term.

19.

20.

21.

22.

23.

24.

Multiply the following decimals.

25.

26.

27.

28.

29.

30.

Divide the following decimals.

31.

32.

33.

34.

1

2

3

4÷ =

1

3

7

8÷ =

1

5

1

2÷ =

3

4

7

8÷ =

6 451 36

.

.×

3 142 20

.

.×

16 2860 125..×

1 20 5

.

.×

7 680 05..×

1

3

2

3÷ =

0 550 75..×

)0 5 1 25. .

)0 20 40 80. .

)0 125 0 25. .

)0 75 0 125. .

4

8

2

3÷ =


(Practice Problems continues on page 20)



35.

36.

Convert the following fractions to decimals and round to the tenth.

37.

38.

39.

40.

41.

42.

1

3=

3

4=

2

3=

1

8=

1

2=

)0 5 7 30. .

)0 3 0 525. .

7

8=



Chapter 1 Post-Test Arithmetic Review

Name Date

Converting Between Arabic Numbers and Roman Numerals

1. 4 � __________

2. IX � __________

Multiplying and Dividing Fractions

3. __________ 5. __________

4. __________ 6. __________

Converting Fractions to Decimals

7. __________

8. __________

9. __________

Multiplying and Dividing Decimals

10. 0.25 × 1.25 � __________

11. 0.125 ÷ 0.25 � __________

12. 1.5 × 0.25 � __________

13. 0.125 ÷ 0.5 � __________

1

2=

3

4=

2

3=

2

4

1

2× =

1

150

1

2÷ =5

6

3

4× =

1

6

1

3÷ =



Exercise 1 .1 Arabic Numbers

and Roman Numerals

1 1 � I2 1 � 1 � II3 1 � 1 � 1 � III4 5 − 1 � IV5 5 � V6 5 � 1 � VI7 5 � 1 � 1 � VII8 5 � 1 � 1 � 1 � VIII9 10 − 1 � IX

10 10 � X11 10 � 1 � XI12 10 � 1 � 1 � XII13 10 � 1 � 1 � 1 � XIII14 10 � 5 − 1 � XIV15 10 � 5 � XV16 10 � 5 � 1 � XVI17 10 � 5 � 1 � 1 � XVII18 10 � 5 � 1 � 1 � 1 � XVIII19 10 � 10 − 1 � XIX20 10 � 10 � XX21 50 − 10 � 1 � 1 � 1 � XLIII22 10 � 10 � 5 − 1 � XXIV23 50 � 5 � LV24 10 � 10 � 10 � 1 � 1 � XXXII25 100 � 1 � 1 � CII26 100 � 50 � CL27 50 � 10 � 10 � 5 � LXXV28 100 − 10 � 1 � 1 � XCII29 50 � 10 � 5 − 1 � LXIV30 50 � 10 � 10 − 1 � LXIX31 II � (1 � 1) � 232 IV � (5 − 1) � 433 VI � (5 � 1) � 634 X � (10) � 1035 VIII � (5 � 1 � 1 � 1) � 836 XIX � (10 − 1 � 10) � 1937 XX � (10 � 10) � 2038 XVIII � (10 � 5 � 1 � 1 � 1) � 1839 I � (1) � 140 XV � (10 � 5) � 1541 III � (1 � 1 � 1) � 342 V � (5) � 543 IX � (10 − 1) � 944 VII � (5 � 1 � 1) � 745 XI � (10 � 1) � 1146 XIV � (10 � 5 − 1) � 14

47 XVI � (10 � 5 � 1) � 1648 XII � (10 � 1 � 1) � 1249 XVII � (10 � 5 � 1 � 1) � 1750 XIII � (10 � 1 � 1 � 1) � 1351 19 � XIX52 XII � 1253 7 � VII54 IX � 955 IV � 456 11 � XI57 VIII � 858 16 � XVI59 XX � 2060 5 � V61 I � 162 18 � XVIII63 VI � 664 2 � II65 III � 366 10 � X67 XIII � 1368 14 � XIV69 XV � 1570 17 � XVII

Exercise 1 .2 Multiplying Fractions

1

2

3

4

5

3

4

5

8

3 5 15

4 8 32

15

32× = × =

× ==

1

3

4

9

1 4 4

3 9 27

4

27× = × =

× ==

2

3

4

5

2 4 8

3 5 15

8

15× = × =

× ==

3

4

1

2

3 1 3

4 2 8

3

8× = × =

× ==

1

8

4

5

1 4 4 4 1

8 5 40 4 10

1

10× = × = ( ) =

× = ( ) ==

ANSWER KEY FOR CHAPTER 1: ARITHMETIC REVIEW


6

7

8

9

10

Exercise 1 .3 Dividing Fractions

1

2

3

4

5

4

7

2

4

4 2 8 4 2

7 4 28 4 7

2

7× = × = ( ) =

× = ( ) ==

4

5

1

2

4 1 4 2 2

5 2 10 2 5

2

5× = × = ( ) =

× = ( ) ==

1

4

1

8

1 1 1

4 8 32

1

32× = × =

× ==

3

8

2

3

3 2 6 6 1

8 3 24 6 4

1

4× = × = ( ) =

× = ( ) ==

2

3

5

8

2 5 10 2 5

3 8 24 2 12

5

12× = × = ( ) =

× = ( ) ==

)3

4

2

3

3

4

3

28 9

81

11

81

1

8÷ = × × =

× == =or

3 3 9

4 2 8

1

9

3

9

1

9

9

3

1

3

1

3÷ = × × = ( ) =

× = ( ) ==or

1 9 9 9

9 3 27 9

)2

3

1

6

2

3

6

13 12

12

44÷ = × × =

× == =or

2 6 12

3 1 3

1

5

4

5

1

5

5

4

1

4

1

4÷ = × × = ( ) =

× = ( ) ==or

1 5 5 5

5 4 20 5

)3

6

4

8

3

6

8

424 24

11÷ = × × =

× == =or

3 8 24

6 4 24

6

7

8

9

10

Exercise 1 .4 Rounding Decimals

1 0.75 � 0.82 0.88 � 0.93 0.44 � 0.44 0.23 � 0.25 0.67 � 0.76 0.27 � 0.37 0.98 � 18 0.92 � 0.99 0.64 � 0.6

10 0.250 � 0.3

Exercise 1 .5 Multiplying Decimals

1

1

5

1

2

1

5

2

1

2

5÷ = × × =

× ==or

1 2 2

5 1 5

1

4

1

2

2 1

2 2

1

2÷ = × = ( ) =

× = ( ) ==1 2 2

4 1 4

1

6

1

3

3 1

3 2

1

2÷ = × = ( ) =

× = ( ) ==1 3 3

6 1 6

2 54 6

..

(1 decimal point)(1 decimal point)

1501

×

0000

(2 decimal points from the right115011 50. tto left)

1

8

2

3

1

8

3

2

3

16÷ = × × =

× ==or

1 3 3

8 2 16

)5

8

5

8

5

8

8

540 40

11÷ = × × =

× == =or

5 8 40

8 5 40



2

3

4

5

6

7

2 560 45..

(2 decimal points)(2 decimal points)×

11280

115201

1024000000

.1520 (4 decimal points froom the right to left)

10 650 05..

(2 decimal points)(2 decimal points× ))

50000

.5325 (4 decimal points from the

325

53250 right to left)

3 90 812

..

(1 decimal point)(1 decimal point)

30

×

000

.12 (2 decimal points from the right to312

3 lleft)

1 450 25..


7729000000

.3625 (4 decimal points from t

25

36250 hhe right to left)

1 983 10

.

.(2 decimal points)(2 decimal points)×

0000

613806

198059400

.1380 (4 decimal points from the right to left)

2 755 0

00

..

(2 decimal points)(1 decimal point)×

003753753 75

1 01 01 0 (3 decimal points from the r. iight to left)

8

9

10

Exercise 1 .6 Dividing Decimals

1

2 50 01

25

..

(1 decimal point)(2 decimal points)×

000

00250 025

00000

(3 decimal points from the ri. gght to left)

7 500 25..


337501500

18751 875

000000

00 (4 decimal points fr. oom the right to left)

5 00 4525

..

(1 decimal point)(2 decimal points)×

00200

2252 25

00000

00 (3 decimal points from the. rright to left)

)3 4 9 6. .

(Move decimal points one place to the righht)

Answer: 2.82 2.8

34 96.006828 027 2

=

80

)2.82

6812



2

3

4

)0 25 12 50. .

(Move decimal points two places to the

)

right)

Answer: 50. 50=

25 1250125

00

50..

)0 56 18 65. .

(Move decimal points two places to the right)

Answer: 33.30 33.3

85168

=

56 1865 001681

.)

170168

20

33 30.

)0 3 0 192. .

(Move decimal points one place to the r

)

iight)

Answer: 0.64 0.6

1 8

=

3 01 92

12120

0 64..

5

6

7

)0 4 12 43. .

(Move decimal points one place to the riight)

Answer: 31.075 31.1

1244

=

4 124 300

0

030

.)

282020

0

31 075.

)0 5 12 50. .

(Move decimal points one place to the r

)

iight)

Answer: 25.0 25=

5 125 0102525

0

25 0..

)0 125 0 25. .

(Move decimal points three places to t

)

hhe right)

Answer: 2. 2

50

=

125 2502

0

2



8

9

10

)0 08 0 085. .


Answer: 1.0625 1.1=

8 8 50008

5048

2016

.)

40400

1 0625.

)1 5 22 5. .

(Move decimal points one place to the ri

)

gght)

Answer: 15. 15

5

5

=

15 2251757

15. .

.

)5 5 16 5. .


)

gght)

Answer: 3. 3

65

=

55 1651

3. .

.

Exercise 1 .7 Converting Fractions

to Decimals

1

2

3

4

1

80 125 0 13 0 1

0 1

8 1 000820164040

0

= = =. . .

: .

.

Answer

)00 125.

)

1

40 25 0 3

0 3

4 1 0082020

25

= =. .

: .

.

.

Answer

0

)

2

50 4

0 4

5 2 020

0

0 4

= .

: .

.

.

Answer

)

3

50 6

0 6

5 3 030

0

0 6

= .

: .

.

.

Answer



5

6

7

8

)

2

30 66 0 7

0 7

3 2 001 8

20182

0 66

= =. .

: .

.

.

Answer

)

6

80 75 0 8

0 8

8 6 0056

40400

0 75

= =. .

: .

.

.

Answer

3

80 375 0 38 0 4

0 4

8 3 0024

605640400

0

= = =. . .

: .

.

.

Answer

)3375

)

1

30 33 0 3

0 3

3 1 0091091

0 33

= =. .

: .

..

Answer

9

10

Practice Problems

1 II2 IV3 V4 XIV5 XIX6 XVI7 68 99 12

10 1711 1912 25

13

14

15

)

3

60 5

0 5

6 3 000

0 5

= .

: .

.

.

Answer

3

)

2

100 2

0 2

10 2 000

0 2

= .

: .

.

.

Answer

2

3 2 6 2 3

4 5 20 2 10

3

10

× = ( ) =× = ( ) =

=

2 5 10 2 5

3 8 24 2 12

5

12

× = ( ) =× = ( ) =

=

1 2 2 2 1

2 3 6 2 3

1

3

× = ( ) =× = ( ) =

=



16

17

18

19

20

21

22

23

24

25

1

2

3

4

1 4 4 2 2

2 3 6 2 3

2

3÷ = × = ( ) =

× = ( ) ==

1

3

7

8

1 8 8

3 7 21

8

21÷ = × =

× ==

1

5

1

2

1 2 2

5 1 5

2

5÷ = × =

× ==

4

8

2

3

4 3 12 4 3

8 2 16 4 4

3

4÷ = × = ( ) =

× = ( ) ==

1

3

2

3

1 3 3 3 1

3 2 6 3 2

1

2÷ = × = ( ) =

× = ( ) ==

4 2 8

5 7 35

8

35

× =× =

=

7 1 7

8 3 24

7

24

× =× =

=

1 1 1

8 8 64

1

64

× =× =

=

3

4

7

8

3 8 24 4 6

4 7 28 4 7

6

7÷ = × = ( ) =

× = ( ) ==

6 451 36..


338701935064500

(4 decimal points fr877208 7720. oom right to left)

26

27

28

29

30

3 142 20

.

.(2 decimal points)(2 decimal points)×

00 06 0

62800

(4 decimal points from

028

690806 9080. right to left)

16 2860 125

..

(3 decimal points)(3 decimal poin× tts)

1628600

.035750 (6 decima

81430325720

20357502 ll points from right to left)

10 560

.2 (1 decimal point)

. (1 decimal point)

00

×

00

.60 (2 decimal points from right to left)0600

70 5.68 (2 decimal points).0 (2 decimal points)×

38400000

038400.3840

00000

(4 decimal points fromm right to left)

00 5.55 (2 decimal points).7 (2 decimal points)×

.

2753850

0000000 4125

00000

(4 decimal points ffrom right to left)



31

32

33

34

)0 20 40 80. .

(Move decimal points two places to the

)

right)

Answer: 204. 204

2 408040

204

=

0

08080

0

)0 5 1 25. .


)

gght)

Answer: 2.5

5 12.510

2.5

2525

0

)0 125 0 25. .

(Move decimal points three places to t

)

hhe right)

Answer: 2. 2

250250

2

=

125

0

)0 75 0 125. .


Answer: 0.166 0.17 = 0.2

12.5007 5

=

75

50045

)

0050

0.166

35

36

37 0.538 0.33 � 0.339 0.75 � 0.840 0.66 � 0.741 0.125 � 0.13 � 0.142 0.875 � 0.88 � 0.9

)0 5 7 30. .

(Move decimal point one place to the rig

)

hht)

Answer: 14.6

73.05

14.65

2320

3030

0

)0 3 0 525. .

(Move decimal points one place to the riight)

Answer: 1.75 = 1.8

5.253

1.73

222115150

)55



Systems of Measurementand Common Equivalents

Objectives

After completing this chapter, you will successfullybe able to:

1. Identify measurements included in the metric,apothecaries’, and household systems.

2. Understand abbreviations used in the metric,apothecaries’, and household systems.

3. Calculate intake and output necessary foraccurate recording in a medical record.

4. Differentiate between Fahrenheit and Celsiusthermometers used for monitoringtemperature.

5. Differentiate between standard time andmilitary time necessary for accurate recordingin a medical record.

Outline

SYSTEMS OF MEASUREMENT 32The Metric System 32The Apothecaries’ System 33The Household System 33INTAKE AND OUTPUT 35Temperature 35TIME 36COMMON EQUIVALENTS 37Practice Problems for Chapter 2: Systems of Measurement

and Common Equivalents 40Post-Test for Chapter 2: Systems of Measurement

and Common Equivalents 43Answer Key for Chapter 2: Systems of Measurement

and Common Equivalents 45

3 1

C H A P T E R 2

Medication calculation need not be difficult if you havea problem-solving method that is easy to understand

and implement. In addition, you need to understand com-mon equivalents and units of measurement to visualize allparts of a medication dosage calculation problem. Under-standing common equivalents and units of measurementwill assist you in preventing medication errors related to incorrect dosage.

This chapter will help you to understand the measurement systems used for medication administration. This knowledge is necessary to accurately implement the problem-solving method of dimensional analysis.


LWBK732_c02_p31-46:lwbk732_ch2 11/20/10 1:42 PM Page 31


SYSTEMS OF MEASUREMENT

Three systems of measurement are used for medication dosage administration:the metric system, the apothecaries’ system, and the household system. To beable to accurately administer medication, you must understand all three of thesesystems.

The Metric SystemThe metric system is a decimal system of weights and measures based on unitsof ten in which gram, meter, and liter are the basic units of measurement. How-ever, gram and liter are the only measurements from the metric system that areused in medication administration. The meter is a unit of distance, the gram(abbreviated g or gm) is a unit of weight, and the liter (abbreviated L) is a unitof volume.

The most frequently used metric units of weight and their equivalents are sum-marized in Box 2.1.

Another way to understand the metric units of weight and their equivalents is tovisualize the relationship between the measurements and equivalents displayed inFigure 2.1.

The most frequently used metric units for volume and their equivalents are sum-marized in Box 2.2.

BOX 2.1 Metric System Units of Weight and Equivalents

1 kilogram (kg)1 gram (g)1 milligram (mg)1 microgram (mcg)1 kg � 1000 g1 g � 1000 mg1 mg � 1000 mcg

1 kg

1 kg = 1000 g

1 g

1 mg

1 mcg1 g = 1000 mg

1 mg = 1000 mcg

1 g

1 mg

Figure 2.1. Metric system units of weight and equivalents.


Another way to understand the metric units of volume and their equivalents isto visualize the relationship between the measurements and equivalents displayedin Figure 2.2.

The Apothecaries’ SystemThe apothecaries’ system is a system of measuring and weighing drugs and solutionsin which fractions are used to identify parts of the unit of measure. The basic units ofmeasurement in the apothecaries’ system include weights and liquid volume.Although the apothecaries’ system may be replaced by the metric system, it is stillnecessary to understand it because some physicians continue to order medicationsusing this system, and they also may include Roman numerals in the medication order.

The most frequently used measurements and equivalents within the apothecaries’system’s units of weight are summarized in Box 2.3, and the most frequently usedmeasurements and equivalents within the apothecaries’ system’s units of volume aresummarized in Box 2.4. Figure 2.3 can help you visualize the equivalents for weightand volume.

The Household SystemThe use of household measurements is considered inaccurate because of the vary-ing sizes of cups, glasses, and eating utensils, and this system generally has beenreplaced with the metric system. However, as patient care moves away from hospi-tals, which use the metric system, and into the community, it is once again neces-sary for the nurse to have an understanding of the household measurement systemto be able to use and teach it to clients and families.

CHAPTER 2 Systems of Measurement and Common Equivalents 3 3

BOX 2.2 Metric System Units of Volume and Equivalents

1 liter (L)1 milliliter (mL)1 L � 1000 mL

1 liter (L)

1 mL

1 liter (L) = 1000 mL Figure 2.2. Metric system units of volume and equivalents.



BOX 2.3 Apothecaries’ System Units of Weight and Equivalents

1 pound (lb)1 ounce (oz)1 dram (dr)1 grain (gr)1 lb � 16 oz1 oz � 8 dr1 dr � 60 gr

BOX 2.4 Apothecaries’ System Units of Volume and Equivalents

1 gallon (gal)1 quart (qt)1 pint (pt)1 fluid ounce (fl oz)1 fluid dram (fl dr)1 minim (M)1 gal � 4 qt1 qt � 2 pt1 pt � 16 fl oz1 fl oz � 8 fl dr1 fl dr � 60 M1 fl oz � 1 oz1 fl dr � 1 dr

Weight

1 pound (lb) 16 ounces (oz)=

Volume

1 gallon (gal) 4 quarts (qt)=

1 pint (pt) 16 fluid ounces (fl oz)=

1 fluid ounce (fl oz) 8 fluid drams (fl dr)=

1 fluid dram (fl dr) 60 minim (M)=

8 pints (pt)=

1 ounce (oz) 8 drams (dr)=

1 dram (dr) 60 grains (gr)=

Figure 2.3. Apothecaries’ system of equivalents for weight and volume. Please note that the figures are notshown to scale.


The most frequently used measurements and equivalents within the householdmeasurement system are summarized in Box 2.5. Figure 2.4 can help you visualizethe equivalents.

INTAKE AND OUTPUT

Now that you have an understanding of the common equivalents, it is time to utilizethat knowledge by calculating the intake from a patient’s meal tray. Monitoring theintake of patients is an extremely important nursing function as it provides infor-mation regarding fluid retention or fluid loss. If a patient is retaining fluid, thephysician or nurse practitioner may need to order a medication to increase theexcretion of the fluid as well as limit fluid intake to prevent fluid overload. If apatient is losing fluid, the physician or nurse practitioner may need to increase fluidintake to prevent dehydration. Regardless of the fluid problem, it is the nurse whomonitors fluid intake and output to report to the physician or nurse practitioner.Figure 2.5 provides an example of a typical Intake and Output Record.

TemperatureClients and families are required to monitor temperature changes associated withvarious medical conditions. Two thermometers may be used for monitoring tem-perature: a Fahrenheit thermometer or a Celsius thermometer. The nurse must beable to explain both of these systems of measurement when discharging clients andfamilies.

The most frequently used measurements for Celsius and Fahrenheit are summa-rized in Figure 2.6.


BOX 2.5 Household Measurement System and Equivalents

1 cup1 tablespoon (tbsp or T )1 teaspoon (tsp or t)1 drop (gtt)1 cup � 8 ounces (oz)2 Tbsp � 1 oz3 tsp � 1 tbsp1 tsp � 60 gtt

1 cup = 8 oz

1 cup

1 tablespoon(tbsp or T)

1 teaspoon (tsp or t)

16 tablespoons(tbsp or T)

3 teaspoons(tsp or t)

60 drops (gtt)

Figure 2.4. Household measurement system andequivalents for volume. Please note that the figuresare not shown to scale.


Box 2.6 summarizes a method for converting between Celsius and Fahrenheit orFahrenheit and Celsius. This easy method requires addition, subtraction, multiplica-tion, or division.

TIME

Another conversion that is necessary to learn is the conversion of standard time tomilitary time. Military time has been adopted by all branches of the armed forces,emergency systems, and health care facilities to avoid confusion regarding the AM(morning) and PM (afternoon/evening) administration of medications. When doc-umenting the administration of medications on the medication administration


Intake and Output Record Name:Date:INTAKE OUTPUT

Oral Voided CatheterDayShift0700

Breakfast

08000900

1000

AM Snack

11001200Lunch13001400PM Snack

ShiftTotal

EveningShift1500

1600

1700

Dinner

1800

1900

200021002200

Evening Snack

ShiftTotalNightShift23002400

010002000300

040005000600

Common Intake Equivalents:Large Glass = 240 mLWater Glass = 180 mLJuice Glass = 120 mLCoffee Cup = 240 mLStyrofoam Cup = 180 mLLarge Milk Carton = 240 mLSmall Milk Carton = 120 mLJello Cup = 120 mLLarge Soup Bowl = 200 mLSmall Soup Bowl = 100 mLHot Cereal = 100 mLIce Cream = 90 mLPopsicle = 80 mLPop Can = 355 mL

ShiftTotal

24-Hour TotalIntake

24-HourTotal

Output

Figure 2.5. Intake and Output Record.


record (MAR), it is essential that the exact time is noted. Military time uses a 24-hour clock and as the hour hand moves around the clock each hour is clearlyidentified from 0100 to 1200. After 1200 (noon), the number 12 is added to eachnumber the second time around the clock. Minutes and seconds are recorded thesame for standard time and military time but no colon (:) is used to separate thehours and minutes in military time. However, if seconds are to be included in mil-itary time then minutes and seconds are separated by a colon (1400:15). Midnightcan be referred to as 0000 or 2400 but after midnight the numbers revert to 0100to 1200. Figure 2.7 displays standard time and military time using a conversiontable and Figure 2.8 displays standard time and military time using the face of aclock. Watches are manufactured with standard time and military time visible onthe face of a clock to eliminate confusion but learning the conversions is the bestmethod of avoiding errors.

COMMON EQUIVALENTS

Sometimes it is necessary to convert from one system to another to accuratelyadminister medication. See Table 2.1 for approximate equivalents for weight andTable 2.2 for approximate equivalents for volume.


Conversion Chart

Celsius to Fahrenheit

35.0 95.0

35.5 95.9

36.0 96.8

36.5 97.7

37.0 98.6

37.5 99.5

38.5 101.3

38.0 100.4

39.0 102.2

39.5 103.1

40.0 104.0

40.5 104.9

41.0 105.8

41.5 106.7

42.0 107.6

Figure 2.6. Conversion chart for Celsius to Fahrenheit.

BOX 2.6 Temperature Conversion Method

To convert from Fahrenheit to Celsius:ºC � (ºF − 32) ÷ 1.8

To convert from Celsius to Fahrenheit:ºF � ºC × 1.8 + 32

ºC � temperature in degrees CelsiusºF � temperature in degrees Fahrenheit



Standard Time Military Time Standard Time Military Time1:00 am 0100 1:00 pm 12+1 = 1300

1:05 am 0105 1:05 pm 1305

2:00 am 0200 2:00 pm

2:10 am 0210 2:10 pm 1410

3:00 am 0300 3:00 pm 12+3 = 1500

3:15 am 0315 3:15 pm 1515

4:00 am 0400 4:00 pm 12+4 = 1600

4:20 am 0420 4:20 pm 1620

5:00 am 0500 5:00 pm 12+5 = 1700

5:25 am 0525 5:25 pm 1725

6:00 am 0600 6:00 pm 12+6 = 1800

6:30 am 0630 6:30 pm 1830

7:00 am 0700 7:00 pm 12+7 = 1900

7:35 am 0735 7:35 pm 1935

8:00 am 0800 8:00 pm 12+8 = 2000

8:40 am 0840 8:40 pm 2040

9:00 am 0900 9:00 pm 12+9 = 2100

9:45 am 0945 9:45 pm 2145

10:00 am 1000 10:00 pm 12+10 = 2200

10:50 am 1050 10:50 pm 2250

11:00 am 1100 11:00 pm 12+11 = 2300

11:55 am 1155 11:55 pm 2355

12:00 pm (noon) 1200 12:00 am 12+12 = 2400

12+2 = 1400

Figure 2.7. Standard Time and Military Time.

12

5674839

2101111100

2300

10002200

09002100

08002000

07001900

01001300

00001200

06001800

02001400

03001500

04001600

05001700

Figure 2.8. Clock with Standard Time and Military Time.


Disclaimer: Converting between measurement systems will often render a differentanswer depending upon which systems and conversions are being used by the student. The answer to the medication calculation problem will ultimately be the sameanswer after rounding either up or down (example: 7.5 L or 7.8 L would both be 8 Lafter rounding up).


TABLE 2.1 Approximate Equivalents for Weight

Metric Apothecaries’

1 kg (1000 g) 2.2 lb1 g (1000 mg) 15 gr60 mg 1 gr

TABLE 2.2 Approximate Equivalents for Volume

Metric Apothecaries’ Household

4000 mL 1 gal (4 qt)1 L (1000 mL) 1 qt (2 pt)500 mL 1 pt (16 fl oz)240 mL 8 oz 1 cup (1 glass)30 mL 1 oz (8 dr) 2 tbsp15 mL 1⁄2 oz (4 dr) 1 tbsp (3 tsp)5 mL 1 dr (60 M) 1 tsp (60 gtt)1 mL 15 M 15 gtt

1 M 1 gtt


Understanding the threesystems of measurementwill assist in preventingmedication errors. Everynurse should have a chartthat clearly identifies theconversions between thethree systems of measure-ment to recheck answersfor accuracy but it is alsothe responsibility of thenurse to memorize theequivalents as a chart maynot always be available.



Summary

This chapter has reviewed the metric, apothecaries’, and household systems of mea-surement. Calculation of intake and output was explained. This chapter alsoreviewed Fahrenheit and Celsius as well as standard time and military time. Toassess your understanding and retention of these systems of measurement, com-plete the following practice problems.

Practice Problems for Chapter 2 Systems of Measurement and

Common Equivalents


Write the correct abbreviation symbols for the following measurements from themetric system:

1. kilogram � 5. liter �

2. gram � 6. milliliter �

3. milligram �

4. microgram �

Write the correct abbreviation symbols for the following measurements from theapothecaries’ system:

7. pound � 12. quart �

8. ounce � 13. pint �

9. dram � 14. fluid ounce �

10. grain � 15. fluid dram �

11. gallon � 16. minim �

Write the correct abbreviation symbols for the following measurements from thehousehold system:

17. tablespoon �

18. teaspoon �

19. drop �

Identify the correct numerical values for the following measurements:

20. 1 kg � ____ lb

21. 1 kg �____ g

22. 1 g �____ mg

23. 1 mg �____ mcg

24. 1 g �____ gr


Calculate the intake for the following meal trays:

25. Breakfast:Coffee Cup � 240 mL (drank 1⁄2)Water Glass � 180 mL (drank 1⁄2 with AM medications)Juice Glass � 120 mL (drank all)Hot Cereal � 100 mL (ate 1⁄2)Total �

26. Lunch:Coffee Cup � 240 mL (drank all)Small Milk Carton � 120 mL (drank all)Large Soup Bowl � 200 mL (ate 1⁄2)Jello Cup � 120 mLTotal �

27. Dinner:Coffee Cup � 240 mL (drank 1⁄4)Large Milk Carton � 240 mL (drank 1⁄2)Ice Cream � 90 mL (ate all)Total �

28. Coffee Cup � 240 mL (drank all)Juice Glass � 120 mL (drank 1⁄2)Hot Cereal � 100 mL (ate all)Total �

29. Milk Carton � 120 mL (drank all)Soup Bowl � 100 mL (ate all)Jello Cup � 120 mL (ate 1⁄2)Total �

Identify the correct numerical values for the following temperatures:

30. 98.6°F � ____ °C

31. 39°C � ____ °F

32. 104.9°F � ____ °C

33. 36°C � ____ °F

34. 101.3°F � ____ °C

Convert the following Standard Times to Military Time:

39. 1:00 am �

40. 5:00 pm �

41. 3:00 am �

42. 8:00 pm �


35. 96.8°F � ____ °C

36. 35°C � ____ °F

37. 100.4°F � ____ °C

38. 39.5°C � ____ °F

43. midnight �

44. 10:15 pm �

45. 6:00 am �

(Practice Problems continue on page 42)



Convert the following Military Times to Standard Time:

46. 0230 �

47. 1600 �

48. 0420 �

49. 1200 �

Identify the correct numerical values for the following measurements:

53. 1 gr �____ mg

54. 1000 mg �____ g

55. 1000 mL �____ L � ____ qt

56. 500 mL �____ pt

57. 240 mL �____ oz

58. 30 mL � ____ oz � ____ tbsp

59. 15 mL � ____ oz � ____ tsp

60. 5 mL � ____ tsp

61. 1 mL � ____ M � ____ gtt

62. 2 mL � ____ gtt

63. 30 gtt � ____ M � ____ mL

64. 4 tbsp � ____ oz � ____ mL

65. 40°C � ____ °F

66. 1 pt � ____ fl oz � ____ mL

67. 2 qt � ____ gal � ____ mL

68. 96.8°F � ____ °C

69. 2000 g � ____ kg � ____ lb

70. gr xv � ____ g � ____ mg

71. 37.5°C � ____ °F

72. 1 oz � ____ dr � ____ mL

73. 32 fl oz � ____ pt � ____ mL

74. 39°C � ____ °F

75. gr xxx � ____ g � ____ mg

76. 240 mL � ____ oz � ____ cup

77. 99.5°F � ____ °C

50. 2110 �

51. 1400 �

52. 1630 �



Chapter 2 Post-Test Systems of Measurement

and Common Equivalents

Name Date

1. 2.2 lb �____ kg

2. 16 fl oz �____ pt

3. 1 tsp �____ mL

4. 15 gr �____ g

5. 1 oz �____ mL

6. 1000 mcg �____ mg

7. 60 mg �____ gr

8. 1 pt �____ mL

9. 1⁄2 tsp �____ mL

10. 1000 mg �____ g

11. 1 L �____ mL

12. 4 qt �____ gal

13. 1 tbsp �____ tsp

14. 1 cup �____ oz

15. 8 oz �____ mL

16. 3 tsp �____ mL

17. 15 gtt �____ M

18. 1 dr �____ mL

19. 15 M �____ mL

20. 1000 g �____ kg


Practice Problems

1 kilogram � kg2 gram � g3 milligram � mg4 microgram � mcg5 liter � L6 milliliter � mL7 pound � lb8 ounce � oz9 dram � dr

10 grain � gr11 gallon � gal12 quart � qt13 pint � pt14 fluid ounce � fl oz15 fluid dram � fl dr16 minim � M17 tablespoon � tbsp18 teaspoon � tsp19 drop � gtt20 1 kg � 2.2 lb21 1 kg � 1000 g22 1 g � 1000 mg23 1 mg � 1000 mcg24 1 g � 15 gr25

Breakfast:Coffee Cup � 240 mL (drank 1⁄2) 120Water Glass � 180 mL (drank 90

1⁄2 with AM medications)

Juice Glass � 120 mL 120(drank all)

Hot Cereal � 100 mL (ate 1⁄2) 50Total � 380 mL

26

Lunch:Coffee Cup � 240 mL 240

(drank all)Small Milk Carton � 120 mL 120

(drank all)Large Soup Bowl � 200 mL (ate 1⁄2) 100Jello Cup � 120 mL (ate all) 120Total � 580 mL

27

Dinner:Coffee Cup � 240 mL (drank 1⁄4) 60Large Milk Carton � 240 mL (drank 1⁄2) 120Ice Cream � 90 mL (ate all) 90Total � 270 mL

28

Coffee Cup � 240 mL (drank all) 240Juice Glass � 120 mL (drank 1⁄2) 60Hot Cereal � 100 mL (ate all) 100Total � 400 mL

29

Milk Carton � 120 mL (drank all) 120Soup Bowl � 100 mL (ate all) 100Jello Cup � 120 mL (ate 1⁄2) 60Total � 280 mL

30 98.6°F � 37°C31 39°C � 102.2°F32 104.9°F � 40.5°C33 36°C � 96.8°F34 101.3°F � 38.5°C35 96.8°F � 36°C36 35°C � 95°F37 100.4°F � 38°C38 39.5°C � 103.1°F

Convert the following Standard Times to MilitaryTime:

39 1:00 am � 010040 5:00 pm � 170041 3:00 am � 030042 8:00 pm � 200043 12:00 am � 240044 10:15 pm � 221545 6:00 am � 0600

Convert the following Military Times to StandardTime:

46 0230 � 2:30 am47 1600 � 4:00 pm48 0420 � 4:20 am49 1200 � 12:00 pm50 2110 � 9:10 pm51 1400 � 2:00 pm52 1630 � 4:30 pm


ANSWER KEY FOR CHAPTER 2: SYSTEMS OF MEASUREMENT AND COMMON EQUIVALENTS


Convert the following:

53 1 gr � 60 mg54 1000 mg � 1 g55 1000 mL � 1 L � 1 qt56 500 mL � 1 pt57 240 mL � 8 oz58 30 mL � 1 oz � 2 tbsp59 15 mL � 1⁄2 oz � 3 tsp60 5 mL � 1 tsp61 1 mL � 15 M � 15 gtt62 2 mL � 30 gtt63 30 gtt � 30 M � 2 mL64 4 tbsp � 2 oz � 60 mL

65 40°C � 104°F66 1 pt � 16 fl oz � 500 mL67 2 qt � 1⁄2 gal � 2000 mL68 96.8°F � 36°C69 2000 g � 2 kg � 4.4 lb70 gr xv � 1 g � 1000 mg71 37.5°C � 99.5°F72 1 oz � 8 dr � 30 mL73 32 fl oz � 2 pt � 1000 mL 74 39°C � 102.2°F75 gr xxx � 2 g � 1800 mg76 240 mL � 8 oz � 1 cup77 99.5°F � 37.5°C



C H A P T E R 3Solving Problems UsingDimensional Analysis

Objectives


1. Define the terms used in dimensional analysis.2. Explain the step-by-step problem-solving

method of dimensional analysis.3. Solve problems involving common

equivalents using dimensional analysis as aproblem-solving method.

D imensional analysis provides a systematic, straight -forward way to set up problems and to organize and

evaluate data. It is not only easy to learn, but also canreduce medication errors when mathematical conversionis required.

Dimensional analysis assists with preventing medica-tion errors by allowing you to visualize all parts of the medication problem and to criti-cally think your way through the problem.

This chapter introduces you to dimensional analysis with a step-by-step explanationof this problem-solving method. The chapter also provides the opportunity to practicesolving problems that involve common equivalents.

Outline

TERMS USED IN DIMENSIONAL ANALYSIS 48THE FIVE STEPS OF DIMENSIONAL ANALYSIS 48Exercise 3.1: Dimensional Analysis 52

Practice Problems for Chapter 3: Solving Problems Using Dimensional Analysis 57

Post-Test for Chapter 3: Solving Problems UsingDimensional Analysis 59

Answer Key for Chapter 3: Solving Problems Using Dimensional Analysis 61

4 7


LWBK732_c03_p47-66:lwbk732_ch3 11/22/10 9:08 AM Page 47


TERMS USED IN DIMENSIONAL ANALYSIS

Dimensional analysis is a problem-solving method that can be used whenever twoquantities are directly proportional to each other and one quantity must be con-verted to the other by using a common equivalent, conversion factor, or conversionrelation. All medication dosage calculation problems can be solved by dimensionalanalysis.

It is important to understand the following four terms that provide the basis fordimensional analysis.

● Given quantity: the beginning point of the problem● Wanted quantity: the answer to the problem● Unit path: the series of conversions necessary to achieve the answer to the

problem● Conversion factors: equivalents necessary to convert between systems of

measurement and to allow unwanted units to be canceled from the problemEach conversion factor is a ratio of units that equals 1.

Dimensional analysis also uses the same terms as fractions: nume rators and denom-inators.

● Numerator � the top portion of the problem● Denominator � the bottom portion of the problem

Some problems will have a given quantity and a wanted quantity that contain onlynumerators. Other problems will have a given quantity and a wanted quantity thatcontain both a numerator and a denominator. This chapter contains only prob-lems with numerators as the given quantity and the wanted quantity.

Once the beginning point in the problem is identified, then a series of con -versions necessary to achieve the answer is established that leads to the problem’ssolution.

Below is an example of the model that is used in solving problems by the dimen-sional analysis method. It also demonstrates the correct placement of the basic termsthat are used in this method.

Unit Path

Conversion Factor Conversion Factor ConversionGiven Quantity for Given Quantity for Wanted Quantity Computation Wanted Quantity

�

THE FIVE STEPS OF DIMENSIONAL ANALYSIS

Once the given quantity is identified, the unit path leading to the wanted quantity isestablished. The problem-solving method of dimensional analysis uses the follow-ing five steps.

1. Identify the given quantity in the problem.2. Identify the wanted quantity in the problem.3. Establish the unit path from the given quantity to the wanted quantity using

equivalents as conversion factors.


4. Set up the conversion factors to permit cancellation of unwanted units. Care-fully choose each conversion factor and ensure that it is correctly placed in thenumerator or denominator portion of the problem to allow the unwanted unitsto be canceled from the problem.

5. Multiply the numerators, multiply the denominators, and divide the product ofthe numerators by the product of the denominators to provide the numericalvalue of the wanted quantity.

The following examples use the five steps to solve problems using dimensional analy-sis. New information that is added in each step appears in red. Lines show thatunwanted units or numbers have been canceled from the unit path. A circle appearsaround the wanted quantity in the unit path.

CHAPTER 3 Solving Problems Using Dimensional Analysis 4 9

E X A M P L E 3 . 1

1 liter (L) equals how many ounces (oz)?

Step 1 Identify the given quantity in the problem.

The given quantity is 1 L.

Step 2 Identify the wanted quantity in the problem.

The wanted quantity is the number of ounces (oz) in 1 L.

Step 3 Establish the unit path from the given quantity to the wantedquantity. You must determine what conversion factors are neededto convert the given quantity to the wanted quantity.

Given quantity: 1 L � 1000 mLWanted quantity: 1 oz � 30 mL

Unit Path


�1 liter (L)

Unit Path


� oz1 liter (L)

(Example continues on page 50)



Step 4 Write the unit path for the problem so that each unit cancels out the preceding unit until all unwanted units are canceled from theproblem except the wanted quantity. Red lines indicate thatunwanted units or numbers have been canceled.

The wanted quantity must be within the numerator portion of theproblem. A red circle around the wanted quantity demonstrates thatthe problem is set up correctly.

Unit Path


� oz1 liter (L) 1000 mL 1 oz

1 liter (L) 30 mL

Unit Path


� oz1 liter (L) 1000 mL 1 oz

1 liter (L) 30 mL

Step 5 After the unwanted units are canceled from the problem, only thenumerical values remain. Multiply the numerators, multiply thedenominators, and divide the product of the numerators by theproduct of the denominators to provide the numerical value for the wanted quantity.

One (1) times (�) any number equals that number, therefore 1smay be automatically canceled from the problem. Other factors thatcan be canceled from the problem include like numerical values inthe numerator and denominator portion of the problem and thesame number of zeroes in the numerator and denominator portionof the problem.

Unit Path


� 33.3 oz1 liter (L) 1000 mL 1 oz

1 liter (L) 30 mL

1000 × 1

1 × 30

1000

30

33.3 oz is the wanted quantity and the answer to the problem.



E X A M P L E 3 . 2

One gallon (gal) equals how many milliliters (mL)?

Step 1 Identify the given quantity in the problem.

The given quantity is 1 gal.

Step 2 Identify the wanted quantity in the problem.

The wanted quantity is the number of milliliters (mL) in 1 gal.

Step 3 Establish the unit path from the given quantity to the wantedquantity by selecting the equivalents that will be used as conversionfactors.

Given quantity: 1 gal � 4 quarts (qt); 1 qt � 1 L

Wanted quantity: 1 L � 1000 mL

Step 4 Write the unit path for the problem so that each unit cancels out(red lines) the preceding unit until all unwanted units are canceled from the problem except the wanted quantity, which is circled.

Step 5 After the unwanted units are canceled from the problem, only thenumerical values remain. Multiply the numerators, multiply thedenominators, and divide the product of the numerators by theproduct of the deno minators to provide the numerical value for thewanted quantity.

4000 mL is the wanted quantity and the answer to the problem.

1 gal�

1 gal� mL

1 gal 4 qt 1 L 1000 mL� mL

1 gal 1 qt 1 L

1 gal 4 qt 1 L 1000 mL 4 × 1000� 4000 mL

1 gal 1 qt 1 L 1



Exercise 3.1 Dimensional Analysis

(See pages 61 –66 for answers)

Use dimensional analysis to change the following units of measurement.

1. Problem: 4 mg � How many g?

Given quantity �

Wanted quantity �

4 mg� g

0.3 L� mL

15 mL� tsp

5000 g� kg

120 lb� kg

2. Problem: 5000 g � How many kg?

Given quantity �

Wanted quantity �

3. Problem: 0.3 L � How many mL?

Given quantity �

Wanted quantity �

5. Problem: 120 lb � How many kg?

Given quantity �

Wanted quantity �

4. Problem: 15 mL � How many tsp?

Given quantity �

Wanted quantity �



6. Problem: 5 gr � How many mg?

Given quantity �

Wanted quantity �

7. Problem: 2 g � How many gr?

Given quantity �

Wanted quantity �

8. Problem: 5 fl dr � How many mL?

Given quantity �

Wanted quantity �

9. Problem: 8 fl dr � How many fl oz?

Given quantity �

Wanted quantity �

5 gr� mg

2 g� gr

5 fl dr� mL

8 fl dr� fl oz

10 M� fl dr

35 kg� lb


10. Problem: 10 M � How many fl dr?

Given quantity �

Wanted quantity �

11. Problem: 35 kg � How many lb?

Given quantity �

Wanted quantity �



12. Problem: 10 mL � How many tsp?

Given quantity �

Wanted quantity �

13. Problem: 30 mL � How many tbsp?

Given quantity �

Wanted quantity �

14. Problem: 0.25 g � How many mg?

Given quantity �

Wanted quantity �

15. Problem: 350 mcg � How many mg?

Given quantity �

Wanted quantity �


Given quantity �

Wanted quantity �

17. Problem: 3 hr � How many minutes?

Given quantity �

Wanted quantity �

10 mL� tsp

30 mL� tbsp

0.25 g� mg

350 mcg� mg

0.75 L� mL

3 hr� min



18. Problem: 3.5 mL � How many M?

Given quantity �

Wanted quantity �


Given quantity �

Wanted quantity �

20. Problem: 225 M � How many tsp?

Given quantity �

Wanted quantity �

21. Problem: 2 gal � How many mL?

Given quantity �

Wanted quantity �

22. Problem: 8 pt � How many gal?

Given quantity �

Wanted quantity �

23. Problem: 16 oz � How many mL?

Given quantity �

Wanted quantity �

3.5 mL� M

500 mcg� mg

225 M� tsp

2 gal� mL

8 pt� gal

16 oz� mL




24. Problem: 2 cup � How many mL?

Given quantity �

Wanted quantity �

25. Problem: 2.5 kg � How many g?

Given quantity �

Wanted quantity �

2 cup� mL

2.5 kg� g



Summary

This chapter has introduced you to dimensional analysis with a step-by-step expla-nation and an opportunity to practice solving problems involving common equiv-alents. To demonstrate your understanding of dimensional analysis and conversionsbetween systems of measurement, complete the following practice problems.

Practice Problems for Chapter 3 Solving Problems Using

Dimensional Analysis


1. Problem: 3–4 mL � How many M?

2. Problem: gtt XV � How many M?

3. Problem: 5–6 gr � How many mg?

4. Problem: How many mL in 3 oz?

5. Problem: 0.5 mg � How many mcg?

6. Problem: 35 gtt � How many mL?

7. Problem: How many mL in 3 qt?

8. Problem: 4 gal � How many qt?

9. Problem: 1.5 cup � How many mL?

10. Problem: 24 oz � How many cups?


12. Problem: 70 kg � How many lb?



15. Problem: 1800 g � How many kg?

16. Problem: 6000 mL � How many qt?

17. Problem: 180 mL � How many oz?

18. Problem: 6 dr � How many mL?


20. Problem: 90 M � How many mL?


22. Problem: 3–4 gr � How many mg?

23. Problem: 1500 mg � How many g?

24. Problem: 3 lb � How many g?


26. Problem: 1––150 gr � How many mg?

27. Problem: 1––300 gr � How many mg?

28. Problem: How many gr in 30 mg?

29. Problem: How many g in 45 gr?

30. Problem: 15 mg � How many mcg?



Chapter 3 Post-Test Solving Problems Using

Dimensional Analysis

Name Date

Use dimensional analysis to solve the following conversion problems:

1. 2045 g � How many lb?

2. 0.004 g � How many mcg?

3. 6 tsp � How many dr?

4. 0.5 L � How many pt?

5. How many L in 250 oz?

6. How many tbsp in 30 mL?

7. How many minims in 60 mL?

8. How many oz in 1800 g?

9. 300 mg � How many gr?

10. How many mg in gr 1⁄4?

11. 20 mL � How many M?

12. How many mcg in 0.75 mg?

13. 1.5 pt � How many mL?

14. How many lb in 84 kg?

15. How many kg in 165 lb?

16. 6500 mcg � How many mg?

17. 24 fl oz � How many mL?

18. 1.89 L � How many mL?

19. How many gal in 64 fl oz?

20. 0.5 L � How many fl oz?



Exercise 3.1 Dimensional Analysis

1

Problem: 4 mg � How many g?Given quantity � 4 mgWanted quantity � gConversion factor � 1 g � 1000 mg

2

Problem: 5000 g � How many kg?Given quantity � 5000 gWanted quantity � kgConversion factor � 1 kg � 1000 g

3

Problem: 0.3 L � How many mL?Given quantity � 0.3 LWanted quantity � mLConversion factor � 1 L � 1000 mL

4

Problem: 15 mL � How many tsp?Given quantity � 15 mLWanted quantity � tspConversion factor � 1 tsp � 5 mL

5

Problem: 120 lb � How many kg?Given quantity � 120 lbWanted quantity � kgConversion factor � 2.2 lb � 1 kg

6

Problem: 5 gr � How many mg?Given quantity � 5 grWanted quantity � mgConversion factor � 1 gr � 60 mg

7

Problem: 2 g � How many gr?Given quantity � 2 gWanted quantity � grConversion factor � 1 g � 15 gr

8

Problem: 5 fl dr � How many mL?Given quantity � 5 fl drWanted quantity � mLConversion factor � 1 fl dr � 5 mL

9

Problem: 8 fl dr � How many fl oz?Given quantity � 8 fl drWanted quantity � fl ozConversion factor � 1 fl dr � 5 mLConversion factor � 1 fl oz � 30 mL

10

Problem: 10 M � How many fl dr?Given quantity � MWanted quantity � fl drConversion factor � 1 mL � 15 MConversion factor � 1 fl dr � 5 mL

4 mg 1 g 4 × 1 4� 0.004 g

1000 mg 1000 1000

5000 g 1 kg 5 × 1 5� 5 kg

1000 g 1 1

0.3 L 1000 mL 0.3 × 1000 300� 300 mL

1 L 1 1

15 mL 1 tsp 15 × 1 15� 3 tsp

5 mL 5 5

120 lb 1 kg 120 × 1 120� 54.5 kg

2.2 lb 2.2 2.2

8 fl dr 5 mL 1 fl oz 8 × 5 × 1 40� 1.3 fl oz

1 fl dr 30 mL 1 × 30 30

5 fl dr 5 mL 5 × 5 25� 25 mL

1 fl dr 1 1

5 gr 60 mg 5 × 60 300� 300 mg

1 gr 1 1

2 g 15 gr 2 × 15 30� 30 gr

1 g 1 1

10 M 1 mL 1 fl dr 10 × 1 × 1 10� 0.13 fl dr

15 M 5 mL 15 × 5 75

ANSWER KEY FOR CHAPTER 3: SOLVING PROBLEMS USING DIMENSIONAL ANALYSIS



11

Problem: 35 kg � How many lb?Given quantity � 35 kgWanted quantity � lbConversion factor � 1 kg � 2.2 lb

12

Problem: 10 mL � How many tsp?Given quantity � 10 mLWanted quantity � tspConversion factor � 1 tsp � 5 mL

13

Problem: 30 mL � How many tbsp?Given quantity � 30 mLWanted quantity � tbspConversion factor � 1 tbsp � 15 mL

14

Problem: 0.25 g � How many mg?Given quantity � 0.25 gWanted quantity � mgConversion factor � 1 g � 1000 mg

15

Problem: 350 mcg � How many mg?Given quantity � 350 mcgWanted quantity � mgConversion factor � 1 mg � 1000 mcg

16


17

Problem: 3 hr � How many minutes?Given quantity � 3 hrWanted quantity � minutesConversion factor � 1 hr � 60 min

18

Problem: 3.5 mL � How many M?Given quantity � 3.5 mLWanted quantity � MConversion factor � 1 mL � 15 M

19

Problem: 500 mcg � How many mg?Given quantity � 500 mcgWanted quantity � mgConversion factor � 1 mg � 1000 mcg

20

Problem: 225 M � How many tsp?Given quantity � 225 MWanted quantity � tspConversion factor � 1 mL � 15 MConversion factor � 1 tsp � 5 mL

30 mL 1 tbsp 30 × 1 30� 2 tbsp

15 mL 15 15

10 mL 1 tsp 10 × 1 10� 2 tsp

5 mL 5 5

35 kg 2.2 lb 35 × 2.2 77� 77 lb

1 kg 1 1

0.25 g 1000 mg 0.25 × 1000 250� 250 mg

1 g 1 1

350 mcg 1 mg 350 × 1 350� 0.35 mg

1000 mcg 1000 1000

0.75 L 1000 mL 0.75 × 1000 750� 750 mL

1 L 1 1

3.5 mL 15 M 3.5 × 15 52.5� 52.5 M

1 mL 1 1

500 mcg 1 mg 500 × 1 500� 0.5 mg

1000 mcg 1000 1000

225 M 1 mL 1 tsp 225 × 1 × 1 225� 3 tsp

15 M 5 mL 15 × 5 75

3 hr 60 min 3 × 60 180� 180 min

1 hr 1 1



21

Problem: 2 gal � How many mL?Given quantity � galWanted quantity � mLConversion factor � 1 gal � 4000 mL

22

Problem: 8 pt � How man gal?Given quantity � ptWanted quantity � galConversion factor � 1 qt � 2 ptConversion factor � 1 gal � 4 qt

23

Problem: 16 oz � How many mL?Given quantity � ozWanted quantity � mLConversion factor � 1 oz � 30 mL

24

Problem: 2 cup � How many mL?Given quantity � cupWanted quantity � mLConversion factor � 1 cup � 8 ozConversion factor � 8 oz � 240 mL

25

Problem: 2.5 kg � How many g?Given quantity � kgWanted quantity � gConversion factor � 1 kg � 1000 g

Practice Problems

1

Problem: 3–4

mL � How many M?Given quantity � 3–

4mL

Wanted quantity � MConversion factor � 1 mL � 15 M

2

Problem: gtt XV � How many M?Given quantity � 15 gttWanted quantity � MConversion factor � 1 gtt � 1 M

3

Problem: 5–6

gr � How many mg?Given quantity � 5–

6gr

Wanted quantity � mgConversion factor � 1 gr � 60 mg

4

Problem: How many mL in 3 oz?Given quantity � 3 ozWanted quantity � mLConversion factor � 1 oz � 30 mL

5

Problem: 0.5 mg � How many mcg?Given quantity � 0.5 mgWanted quantity � mcgConversion factor � 1 mg � 1000 mcg

2 gal 4000 mL 2 × 4000 8000� 8000 mL

1 gal 1 1

16 oz 30 mL 16 × 30 480� 480 mL

1 oz 1 1

8 pt 1 qt 1 gal 8 × 1 × 1 8� 1 gal

2 pt 4 qt 2 × 4 8

2 cup 8 oz 240 mL 2 × 8 × 240 3840� 480 mL

1 cup 8 oz 1 × 8 8

2.5 kg 1000 g 2.5 × 1000 2500� 2500 g

1 kg 1 1

3–4

mL 15 M 3–4

× 15 3–4

× 15–1

45–4

11.25 M �11.25 M

1 mL 1 1 1 1

0.5 mg 1000 mcg 0.5 × 1000 500� 500 mcg

1 mg 1 1

3 oz 30 mL 3 × 30 90� 90 mL

1 oz 1 1

15 gtt 1 M 15� 15 M

1 gtt

5–6

gr 60 mg 5–6

× 60 5–6

× 60–1

300—650

� 50 mg1 gr 1 1 1 1



6

Problem: 35 gtt � How many mL?Given quantity � 35 gttWanted quantity � mLConversion factor � 1 gtt � 1 MConversion factor � 15 M � 1 mL

7

Problem: How many mL in 3 qt?Given quantity � 3 qtWanted quantity � mLConversion factor � 1 qt � 1000 mLConversion factor � 1 cc � 1 mL

8

Problem: 4 gal � How many qt?Given quantity � 4 galWanted quantity � qtConversion factor � 1 gal � 4 qt

9

Problem: 1.5 cup � How many mL?Given quantity � 1.5 cupWanted quantity � mLConversion factor � 1 cup � 240 mL

10

Problem: 24 oz � How many cups?Given quantity � 24 ozWanted quantity � cupsConversion factor � 1 cup � 8 oz

11

Problem: 132 lb � How many kg?Given quantity � 132 lbWanted quantity � kgConversion factor � 2.2 lb � 1 kg

12

Problem: 70 kg � How many lb?Given quantity � 70 kgWanted quantity � lbConversion factor � 1 kg � 2.2 lb

13

Problem: 750 mcg � How many mg?Given quantity � 750 mcgWanted quantity � mgConversion factor � 1000 mcg � 1 mL

14


15

Problem: 1800 g � How many kg?Given quantity � 1800 gWanted quantity � kgConversion factor � 1000 g � 1 kg

24 oz 1 cup 24 × 1 24� 3 cups

8 oz 8 8

1.5 cup 240 mL 1.5 × 240 360� 360 mL

1 cup 1 1

4 gal 4 qt 4 × 4 16� 16 qt

1 gal 1 1

3 qt 1000 mL 3 × 1000 3000� 3000 mL

1 qt 1 1

35 gtt 1M 1 mL 35 × 1 × 1 35� 2.3 mL

1 gtt 15 M 1 × 15 15

132 lb 1 kg 132 × 1 132� 60 kg

2.2 lb 2.2 2.2

70 kg 2.2 lb 70 × 2.2 154

1 kg 1 1� 154 lb

750 mcg 1 mg 75 × 1 75� 0.75 mg

1000 mcg 100 100

0.5 L 1000 mL 0.5 × 1000 500� 500 mL

1 L 1 1

1800 g 1 kg 18 × 1 18� 1.8 kg

1000 g 10 10



16

Problem: How many qt in 6000 mL?Given quantity � 6000 mLWanted quantity � qtConversion factor � 1000 mL � 1 qt

17

Problem: 180 mL � How many oz?Given quantity � 180 mLWanted quantity � ozConversion factor � 30 mL � 1 oz

18

Problem: 6 dr � How many mL?Given quantity � 6 drWanted quantity � mLConversion factor � 1 dr � 5 mL

19


20

Problem: How many mL in 90 M?Given quantity � 90 MWanted quantity � mLConversion factor � 1 mL � 15 M

21

Problem: 145 lb � How many kg?Given quantity � 145 lbWanted quantity � kgConversion factor � 1 kg � 2.2 lb

22

Problem: 3–4

gr � How many mg?Given quantity � 3–

4gr


23

Problem: How many g in 1500 mg?Given quantity � 1500 mgWanted quantity � gConversion factor � 1 g � 1000 mg

24

Problem: 3 lb � How many g?Given quantity � 3 lbWanted quantity � gConversion factor � 2.2 lb � 1000 g

25


180 mL 1 oz 18 × 1 18� 6 oz

30 mL 3 3

6 dr 5 mL 6 × 5 30� 30 mL

1 dr 1 1

0.125 mg 1000 mcg 0.125 × 1000 125�125 mcg

1 mg 1 1

90 M 1 mL 90 × 1 90� 6 mL

15 M 15 15

145 lb 1 kg 145 × 1 145� 65.9 kg

2.2 lb 2.2 2.2

3–4

gr 60 mg 3–4

× 60–1

180––4

45� 45 mg

1 gr 1 1 1

1500 mg 1 g 1500 × 1 1500� 15 g

1000 mg 1000 1000

3 lb 1000 g 3 × 1000 3000� 1363.6 g

2.2 lb 2.2 2.2

0.80 mg 1000 mcg 0.80 × 1000 800� 800 mcg

1 mg 1 1

6000 mL 1 qt 6000 × 1 6000� 6 qt

1000 mL 1000 1000



26

Problem: 1––150

gr � How many mg?Given quantity � 1––

150gr


27

Problem: 1––300

gr � How many mg?Given quantity � 1––

300gr


28

Problem: How many gr in 30 mg?Given quantity � 30 mgWanted quantity � grConversion factor � 1 gr � 60 mg

29

Problem: How many g in 45 gr?Given quantity � 45 grWanted quantity � gConversion factor � 1 g � 15 gr

30

Problem: 15 mg � How many mcg?Given quantity � 15 mgWanted quantity � mcgConversion factor � 1 mg � 1000 mcg

1––150

gr 60 mg 1––150

× 60–1

60––150

0.4� 0.4 mg

1 gr 1 1 1

1––300

gr 60 mg 1––300

× 60–1

60––300

0.2� 0.2 mg

1 gr 1 1 1

15 mg 1000 mcg 15 × 1000 15000� 15000 mcg

1 mg 1 1

30 mg 1 gr 30 × 1 30� 0.5 gr

60 mg 60 60

45 gr 1 g 45 × 1 45� 3 g

15 gr 15 15


One-Factor Medication Problems

Objectives


1. Interpret medication orders correctly, basedon the six rights of medication administration.

2. Identify components from a drug label thatare needed for accurate medicationadministration and documentation.

3. Describe the different routes of medicationadministration: tablets and capsules, liquidsgiven by medicine cup or syringe, andparenteral injections using different types of syringes.

4. Calculate medication problems accuratelyfrom the one-factor–given quantity to theone-factor–wanted quantity using thesequential or random method of dimensionalanalysis.

Outline

INTERPRETATION OF MEDICATION ORDERS 68Right Patient 68Right Drug 68Right Dosage 69Right Route 69Right Time 69Right Documentation 69Exercise 4.1: Interpretation of Medication Orders 70

Medication Administration Record 70Exercise 4.2: Medication Administration Record 71

ONE-FACTOR MEDICATION PROBLEMS 72Principles of Rounding 75Exercise 4.3: One-Factor Medication Problems 78

COMPONENTS OF A DRUG LABEL 78Identifying the Components 78Exercise 4.4: Identifying the Components of Drug Labels 79

Solving Problems With Components of Drug Labels 81Exercise 4.5: Problems With Components of Drug Labels 83

ADMINISTERING MEDICATION BY DIFFERENT ROUTES 84

Enteral Medications 84Exercise 4.6: Administering Enteral Medications 89

Parenteral Medications 90Exercise 4.7: Administering Parenteral Medications 95

Practice Problems for Chapter 4: One-Factor Medication Problems 97

Post-Test for Chapter 4: One-Factor Medication Problems 103

Answer Key for Chapter 4: One-Factor Medication Problems 109

6 7

C H A P T E R 4

For accurate administration of medication, the six rightsof medication administration form the foundation of

communication between the person writing the medicationorder and the person reading the medication order.




INTERPRETATION OF MEDICATION ORDERS

Physicians and nurse practitioners order medications using the six rights of med-ication administration including the:

1. Right patient 4. Right route2. Right drug 5. Right time3. Right dosage 6. Right documentation

Right PatientMany medication errors can be prevented by correctly identifying the right patient.Patients in the hospital setting wear identification bands, whereas other facilitiesmay use a photograph to identify the right patient.

Regardless of the identification method, the medication order must correspondto the identification of the patient. Checking identification and asking patients tostate their names assists in reducing medication errors. It is also important to “lis-ten” to the patient. If the patient states, “I don’t take a blue pill,” go back and checkthe medication order for correctness.

Right DrugMedications can be ordered using their trade name or generic name.Examples:

1. Tagamet® or cimetidine2. Cipro® or ciprofloxacin hydrochloride

It is the responsibility of the nurse to look up a medication before administrationto ensure that the right drug is being administered.

It is the responsibility of the nurse to know the classification of the drug beingadministered and that the drug corresponds with the patient diagnosis. Many drugshave similar names.Example:

1. Celebrex® (an anti-inflammatory)2. Celexa® (an antidepressant)

It is also the responsibility of the nurse to know the side effects of the drug beingadministered. The nurse must be aware of any patient allergies before medicationadministration to ensure safety of the patient. Allergies should be clearly recorded onmedication records or a patient should wear an allergy bracelet.


Medication errors can beprevented by carefullyadhering to these sixrights, understanding theimportant concepts thatapply to each right, andutilizing a nursing drug ref-erence to provide accurateinformation for each med-ication administered.

Once you are able tointerpret the importantcomponents of a medica-tion order, you can per-form accurate calculationsfor the correct dosageusing dimensional analy-sis. If you cannot correctlyinterpret the componentsof a medication order(illegible prescriptionorder), call the physicianor nurse practitioner forclarification to preventmedication errors.

The physician or nurse practitioner writes a medication order using the sixrights, and the nurse administers the medication to the patient based on the sixrights. There may be a slight variation in the way each person writes a medicationorder, but information pertaining to the six rights should be included in the med-ication order to ensure safe administration by the nurse and the prevention ofmedication errors.

To calculate the change from a one-factor-given quantity to a one-factor-wanted quantity using dimensional analysis, it is necessary to have aclear understanding of the six rights of medication administration. This chap-ter teaches you to interpret medication orders correctly and to calculate med-ication problems accurately using dimensional analysis.


Because it is impossible to know all medications, the nurse can use a nursingdrug reference to look up medications to ensure accuracy and prevent medicationerrors.

Right DosageMedications are available in different dosages. It is the responsibility of the nurse toensure that the right dosage is administered. The pharmacy may supply the exactdosage ordered or the dosage may need to be converted using a common equivalentor calculated based on the weight of the patient. If the medication must be reconsti-tuted, the correct diluent must be used for reconstitution. If a patient is to receive atablet but has difficulty swallowing, the nurse must obtain an order to have the med-ication changed to an elixir. Medication orders are to be administered exactly in thedosage ordered. A nursing drug reference assists with preventing medication errorsby supplying information regarding the dosages of medications that can be safelyadministered to a patient based on age and weight.

Right RouteMedications may be administered by different routes including oral (tablets, capsules,or liquid), parenteral (intradermal, subcutaneous, intramuscular, or intravenous), orcutaneous (skin and mucous membranes). Improper medication administration tech-niques (crushing an enteric-coated tablet, opening a capsule, or giving an injectionusing the wrong route) are considered medication errors. A nursing drug reference pro-vides information regarding the routes that can be safely used to administer medica-tion and eliminate medication errors. It is the responsibility of the nurse to use thisinformation to safely administer the medication to the patient using the right route.

Right TimeMedications are ordered and need to be administered at specific times to ensure theeffective absorption of the medication. Failure to administer a medication on time orfailure to document the administration of a medication is a medication error of omis-sion. Some medications are ordered before meals (ac), after meals (pc), or at bedtime.Other medications may be ordered based on frequency of time (once a day [qd], twicea day [bid], three times a day [tid], or four times a day [qid]). A nursing drug referenceprovides the nurse with the appropriate information to ensure that the medication iseffectively and safely administered to eliminate a medication error based on adsorp-tion. Most facilities allow a window of administration that is usually 30 minutes beforeor 30 minutes after the prescribed time. It is the responsibility of the nurse to use thisinformation to safely administer the medication to the patient at the right time.

Once you are able to interpret the important components of an order for med-ication, you can perform accurate calculations for the correct drug dosage by usingdimensional analysis.

Right DocumentationDocumentation is the sixth “right of medication administration” and should be com-pleted as soon as possible after the administration of the medication. Documenta-tion is an important right that can prevent medication errors related to over- orunder-medication. The general rule of documentation is “if you didn’t chart it . . . youdidn’t do it” therefore medication should never be charted before administration ofthe medication. Documentation should follow medication administration andinclude documentation regarding refusals, delays, and responses (including adverseeffects) of medication administration.

CHAPTER 4 One-Factor Medicat ion Problems 6 9


Medication Administration RecordA Medication Administration Record or MAR is a document used to chart the admin-istration of medication. In an effort to reduce medication errors related to misinter-pretation of hand-writing, many health care facilities are now using an ElectronicMedication Administration Record or eMAR. Documentation must occur on the MARafter the administration of a medication as well as if a medication is not administered.If a medication is not administered, the reason that the medication was not adminis-tered must also be written on the MAR. A sample MAR will provide an opportunityto practice the sixth right of medication administration using Exercise 4.2.


Exercise 4.1 Interpretation of Medication Orders


In the following medication orders, identify the six rights of medication admin-istration.

1. Give gr 10 aspirin to Mrs. Anna Clark orally every 4 hours as needed forfever.

a. Right patient _____________

b. Right drug _____________

c. Right dosage _____________

d. Right route _____________

e. Right time _____________

f. Right documentation _____________

2. Administer PO to Mr. William Smith, Advil (ibuprofen) 400 mg every 6 hours for arthritis.


b. Right drug _____________


d. Right route _____________

e. Right time _____________


3. Tylenol (acetaminophen) gr 10 PO every 4 hours for Mr. Thomas Jones prnfor headache.


b. Right drug _____________


d. Right route _____________

e. Right time _____________




Exercise 4.2 Medication Administration Record

(Answers in Exercise 4.1 f, p. 109.)

Date/Time/ Reason/

Name Medication Route Effects Initials

Mrs. Anna Clark Aspirin 10 gr ID# ________ orally every Allergies: ____ 4 hours as

needed

Mr. William Smith AdvilID# ________ (Ibuprofen)Allergies: ____ 400 mg

PO every 6 hours

Mr. Thomas Jones Tylenol ID# ________ (acetamino-Allergies: ____ phen) 10 gr

PO every 4 hours PRN

Initials Staff Signature

Date/Time/ Reason/

Name Medication Route Effects Initials

Initials Staff Signature



ONE-FACTOR MEDICATION PROBLEMS

Medication problems can be easily solved using the five steps of dimensionalanalysis:

● The first step in interpreting any physician’s order for medication is to identify the given quantity or the exact dosage that the physician ordered.

● The second step is to identify the wanted quantity or the answer to the med-ication problem.

● The third step is to establish the unit path from the given quantity to thewanted quantity, using equivalents as conversion factors to complete theproblem. Identification of the available dosage of medicine (dose on hand) isconsidered part of the unit path.

● The fourth step is to set up the problem to cancel out unwanted units.● The fifth step is to multiply the numerators, multiply the denominators, and

divide the product of the numerators by the product of the denominators toprovide the numerical value of the wanted quantity or answer to the problem.

You may choose to implement either the sequential method or the randommethod of dimensional analysis.

The sequential method of dimensional analysis requires ordering and reorga-nizing the conversion factors into the unit path in a logical, sequential method. Thesequential method requires identification of the given quantity followed by theappropriate conversion factors to allow logical progression and cancellation towardthe wanted quantity, keeping in mind correct placement for cancellation. Thesequential method is based on a logical process and placement of factors into theunit path. Examples 4.1 to 4.3 demonstrate the use of the sequential method ofdimensional analysis.

The random method of dimensional analysis allows for indiscriminate place-ment of conversion factors into the unit path in an arbitrary, random method. Therandom method requires identification of the given quantity and the wanted quan-tity but permits individualized placement of the conversion factors into the unitpath. The random method focuses on the correct placement of the conversion fac-tor (dose on hand) in the unit path to correspond with the answer (wanted quan-tity). If the wanted quantity is tablets, then tablets must be in the numerator positionin the unit path with the dosage in the denominator position. The random methodallows for canceling of conversion factors without regard to logical, sequentialplacement of the conversion factors. Example 4.4 demonstrates the use of the ran-dom method of dimensional analysis.

Below is an example of a one-factor problem showing the placement of compo-nents used in dimensional analysis.

Given QuantityConversion Factor for Given Quantity

Conversion Factor forWanted Quantity

Conversion Computation Wanted Quantity

10 gr

Unit Path

tablets

5 gr

10

52 tablets�


The given quantity is the doctor’s order and should contain all six rights of themedication order, except documentation.






10 gr

Unit Path

tablets

5 grtablets�

Thin kingit

ThroughBoth 10 gr and tablets arenumerators without adenominator. This is called aone- factor medication prob-lem because the given quan-tity and the wanted quantity contain only numerators.

The dose on hand (5 gr/tablet) is an equivalent thatis used as a conversion fac-tor and is factored into theunit path.

The unwanted units (gr)can be canceled from theproblem leaving the wantedquantity (tablets) in thenumerator.

The sequential method ofdimensional analysis hasbeen used to factor in thedose on hand, which allowsthe previous unit (given quantity) to be canceled.When using the sequentialmethod, the conversion fac-tor that is factored in always cancels out the precedingunit.




10 gr

Unit Path

�





10 gr

Unit Path

tablets�

E X A M P L E 4 . 1

The physician orders gr 10 aspirin orally every 4 hours, as needed forfever. The unit dose of medication on hand is gr 5 per tablet (5 gr/tab).

How many tablets will you administer?

Given quantity � 10 grWanted quantity � tabletsDose on hand � gr/tablet

Step 1 Identify the given quantity (the physician’s order).

Step 2 Identify the wanted quantity (the answer to the problem).

Step 3 Establish the unit path from the given quantity to the wanted quantity using equivalents as conversion factors.


Step 4 Set up the problem to allow cancellation of unwanted units and circle the wanted quantity within the unit path to demonstrate correct placement.

Step 5 Multiply the numerators, multiply the denominators, and divide theproduct of the numerators by the product of the denominators toprovide the numerical value for the wanted quantity.

2 tablets is the wanted quantity and the answer to the problem.




10 gr

Unit Path

tablets

5 gr

10

52 tablets�




10 gr

Unit Path

tablets

5 grtablets�

400 mg�

E X A M P L E 4 . 2

Administer PO Advil (ibuprofen) 400 mg every 6 hours for arthritis. Thedosage on hand is 200 mg/tablet.

How many tablets will you give?

Given quantity � 400 mgWanted quantity � tabletsDose on hand � 200 mg/tablet

Step 1 Identify the given quantity.



When preparing to admin-ister more than two tabletsor capsules to a patient,always recalculate theanswer to ensure the cor-rect answer and preventmedication errors. Rarelydoes a patient receive morethan two tablets or cap-sules of a medication. Ifmore than two tablets orcapsules are being adminis-tered, a different dosage ofthe medication should bediscussed with the pharmacist.

Thin kingit

ThroughThe sequential method ofdimensional analysis hasbeen used to set up theproblem. The unwanted units(mg) have been canceledfrom the unit path by cor-rectly factoring in the doseon hand (200 mg/tablet). Thesame number of zeroes hasalso been canceled from thenumerator and denominator.


Principles of RoundingIf an answer does not result in a whole number, but instead a decimal in the tenths(4.7) or hundredths (4.75), the answer can be rounded up or down to allow foradministration of the medication. Some medications may not require roundingwhen the exact amount of medication calculated needs to be administered.

If the tablets are scored, a half of the tablet can be administered. If a tablet is notscored, a decision must be made by the nurse whether to give one or two tablets. If aliquid medication to be administered involves decimals, then the nurse must make adecision regarding the amount of medication to be given.

If the number following the decimal is 5 or greater, then the number is rounded up.Example in the tenths: 4.7 → 5Example in the hundredths: 4.75 → 4.8

If the number following the decimal is less than 5, then the number is roundeddown.Example in the tenths: 4.4 → 4Example in the hundredths: 4.42 → 4.4

Step 2 Identify the wanted quantity.

Step 3 Establish the unit path from the given quantity to the wanted quantity using equivalents as conversion factors.

Step 4 Set up the problem to allow cancellation of unwanted units and circle the wanted quantity within the unit path to demonstrate correct placement.

Step 5 Multiply the numerators, multiply the denominators, and divide the product of the numerators by the product of the denominators to provide the numerical value of the wanted quantity.



400 mg tablet 4� 2 tablets

200 mg 2

400 mg tablet� tablets

200 mg

400 mg tablet� tablets

200 mg

400 mg� tablets


Understanding the princi-ples of rounding will pre-vent over- or undermed-ication, both of which areclassified as medicationerrors.



E X A M P L E 4 . 3

Tylenol (acetaminophen) gr 10 PO every 4 hours for headache. The unitdose of medication on hand is 325 mg per caplet.

How many caplets will you give?

Given quantity � 10 grWanted quantity � capletsDose on hand � 325 mg/caplet



Step 3 Establish the unit path from the given quantity to the wantedquantity using equivalents as conversion factors.

Step 4 Set up the problem to allow cancellation of unwanted units andcircle the wanted quantity within the unit path to demonstratecorrect placement.

Step 5 Multiply the numerators, multiply the denominators, and divide the product of the numerators by the product of the denominators toprovide the numerical value of the wanted quantity.

1.8 caplets is the wanted quantity and the answer to the problem, but, by using

the rounding rule, 2 caplets would be given.

10 gr 60 mg caplet 10 × 60 600� 1.8 caplets

1 gr 325 mg 1 × 325 325

10 gr�

10 gr� caplets

10 gr 60 mg caplet� caplets

1 gr 325 mg

10 gr 60 mg caplet� caplets

1 gr 325 mg


Following the principles ofrounding, two capletswould be given as the cor-rect dosage of medication.

Thin kingit

ThroughThe sequential method of dimensional analysis hasbeen used. The unwantedunit (gr) has been canceledby factoring in a conversionfactor (1 gr � 60 mg).

The dose on hand (325mg/ caplet) is factored intothe unit path, which allowsthe unwanted unit (mg) tobe canceled.

The remaining unit (caplet)is in the numerator and cor-rectly correlates with thewanted quantity in thenumerator.


Dimensional analysis is a problem-solving method that uses critical thinking, nota specific formula. Therefore, the important concept to remember is that allunwanted units must be canceled from the unit path. The random method ofdimensional analysis can also be used when solving medication problems. Whenusing the random method of dimensional analysis, the focus is on the correct place-ment of the conversion factor. It must correlate with the wanted quantity in thenumerator portion of the unit path, without considering the preceding units.


Thin kingit

ThroughWhen using the randommethod, the focus is on thecorrect placement of theconversion factor to corre-spond with the wantedquantity. The problem is setup correctly as long as thedose on hand (caplet) corre-lates with the wanted quan-tity (caplet), both in thenumerator.

A conversion factor (1 gr �60 mg) is factored into theproblem to cancel out theunwanted units (gr and mg).The remaining unit (caplet)correlates with the wantedquantity.

E X A M P L E 4 . 4

The random method of dimensional analysis will be used to calculate the answer for Example 4.3.



Step 3 Establish the unit path from the given quantity to the wantedquantity using equivalents as conversion factors.

Step 4 Set up the problem to allow cancellation of unwanted units andcircle the wanted quantity within the unit path to demonstratecorrect placement.

Step 5 Multiply the numerators, multiply the denominators, and divide the product of the numerators by the product of the denominators toprovide the numerical value of the wanted quantity.

1.8 caplets is the wanted quantity and the answer to the problem,

but, by using the rounding rule, 2 caplets would be given.

10 gr� caplet

10 gr�

10 gr caplet� caplet

325 mg

10 gr caplet 60 mg� caplet

325 mg 1 gr

10 gr caplet 60 mg 10 × 60 600� 1.8 caplets

325 mg 1 gr 325 × 1 325


COMPONENTS OF A DRUG LABEL

All medications (stock and unit dose) are labeled with a drug label thatincludes specific information to assist in the accurate administration of themedication.

Identifying the ComponentsInformation on the drug label includes:

● Name of the drug, including the trade name (name given by the pharmaceuti-cal company identified with a trademark symbol) and the generic name (chem-ical name given to the drug)

● Dosage of medication (the amount of medication in each tablet, capsule, orliquid)

● Form of medication (tablet, capsule, or liquid)● Expiration date (how long the medication will remain stable and safe

to administer)● Lot number or batch number (the manufacturer’s batch series for this med-

ication)● Manufacturer (the pharmaceutical company that produced the medication)


Exercise 4.3 One-Factor Medication Problems


1. The physician orders Achromycin (tetracycline) 0.25 g PO every 12 hours

for acne. The dosage of medication on hand is 250 mg per capsule.

How many capsules will you give?

2. Administer phenobarbital gr 1⁄2 PO tid for sedation. The dosage on hand is

15 mg/tablet.


3. Give 0.5 g Diuril PO bid for hypertension. Unit dose is 500 mg per tablet.


4. Order: Restoril 0.03 g PO at bedtime for sedation. Supply: Restoril 30-mg

capsules.


5. Order: Thorazine gr 1⁄2 PO tid for singultus. Supply: Thorazine 30-mg

capsules.


▲▲

▲▲

▲


Before administering any medication, the nurseshould check the expira-tion date on the label.Administering a medica-tion that has expired wouldbe considered a medicationerror.



E X A M P L E 4 . 5

a. Trade name of the drug: Zantacb. Generic name of the drug: ranitidine hydrochloridec. Dosage of medication: 300 mg per tabletd. Form of medication: 30 tabletse. Expiration date:f. Lot number or batch number:

Zantac® 300(ranitidine hydrochloride)tablets, USP300 mg

300 mg 30 Tablets

NDC 0173-0393-40

LOT

EX

P.

Usual Adult Dosage: One tablet dailyafter the evening meal, at bedtime,or as directed by a physician.See package insert for full prescribinginformation.Store between 15° and 30°C (59°and 86°F) in a dry place. Protect from light.Replace cap securety after each opening.

Zantac is a registered trademark ofWarner-Lambert Company, usedunder license.

Each tablet contains300 mg of ranitidineas ranitidinehydrochloride.

GlaxoSmithKlineResearch Triangle Park, NC 277094133749

0173

-039

3-40

Rev. 6/01

Zantac

300

Copyright GlaxoSmithKline. Used with Permission.

Exercise 4.4 Identifying the Components of Drug Labels


1.

a. Trade name of the drug _____________

b. Generic name of the drug _____________

c. Dosage medication _____________

d. Form of medication _____________

e. Expiration date _____________

Courtesy of Bayer Corporation Pharmaceutical Division.




f. Batch number _____________

g. Manufacturer _____________

2.








3.








Copyright GlaxoSmithKline. Used with permission.

Courtesy of the Upjohn Company.


Solving Problems With Components of Drug LabelsOnce you are able to identify the components of a drug label, you can use criticalthinking to solve problems with dimensional analysis.


E X A M P L E 4 . 6

The physician orders Cipro 750 mg PO every 12 hours for a bacterial infection.


Given quantity � 750 mgWanted quantity � tabletsDose on hand � 500 mg/tablet

Sequential method:

1.5 tablets is the wanted quantity and the answer to the problem.

Courtesy of Bayer Corporation Pharmaceutical Division.

750 mg tablet 75� 1.5 tablets

500 mg 50


The wanted quantity andthe answer to the problemis 1.5 tablets. A scoredtablet can be cut in halfallowing the exact dosageto be administered. To pre-vent medication errors,always check with a phar-macist before altering theform of any medication.

E X A M P L E 4 . 7

Administer trimethobenzamide HCl 200 mg PO qid for nausea.


TRIMETHO-

BENZAMIDE HCI

100 Capsules

100 mg Store at room temperature.Container not for household use.Dispense in a well-closed container.Each capsule contains 100 mgtrimethobenzamide hydrochloride.Dosage: See accompanyingprescribing information.Important: Use safetyclosures when dispensingthis product unless otherwisedirected by physician orrequested by purchaser.

N

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EX

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disp

ensi

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ithou

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31




Given quantity � 200 mgWanted quantity � capsulesDose on hand � 100 mg/capsules

Sequential method:

2 capsules is the wanted quantity and the answer to the problem.

200 mg capsules 2� 2 capsules

100 mg 1

E X A M P L E 4 . 8

Order: Halcion 0.25 mg PO at bedtime prn.


Given quantity � 0.25 mgWanted quantity � tabletsDose on hand � 0.125 mg/tablet

Sequential method:


0.25 mg tablet 0.25� 2 tablets

0.125 mg 0.125




Exercise 4.5 Problems With Components of Drug Labels


1. Order: methylphenidate 10 mg PO before breakfast and lunch for attention-

deficit hyperactivity disorder (ADHD)

How many tablets will you give? ________________

2. Order: Xanax 500 mcg PO bid for anxiety


3. Order: Tolinase 375 mg PO every AM ac for type 2 diabetes mellitus


▲▲

▲

Courtesy of Medeva Pharmaceuticals.


Courtesy of the Upjohn Company.(Exercise continues on page 84)



4. Order: vitamin B12 2.5 mg daily as a daily vitamin supplement

How many tablets will you give? _____________

5. Order: trimethobenzamide HCl 250 mg PO qid prn for nausea

How many capsules will you give? _____________

▲▲

Courtesy of Vitaline Corporation.

TRIMETHO-

BENZAMIDE HCI

100 Capsules

250 mg Store at room temperature.Container not for householduse. Dispense in a well-closedcontainer. Each capsulecontains 250 mgtrimethobenzamidehydrochloride.Usual Adult Dosage: Onecapsule 3 or 4 times daily.See accompanyingprescribing information.Important: Use safetyclosures when dispensingthis product unlessotherwise directed byphysician or requestedby purchaser.

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31

ADMINISTERING MEDICATION BY DIFFERENT ROUTES

Medication may be administered by various routes, including oral, parenteral, orintravenous, involving tablets, capsules, or liquid.

Enteral MedicationsOral (PO) medications are administered using tablets, caplets, capsules, or liquid.Tablets and caplets may be scored, which permits a more accurate administrationwhen one fourth or one half of a tablet must be given.

Tablets and caplets may also be enteric coated, which allows the medication tobypass disintegration in the stomach to decrease irritation, and then later breakdown in the small intestine for absorption. Enteric-coated tablets and caplets shouldnever be crushed, because such medications irritate the stomach.


Crushing enteric-coatedtablets and caplets wouldbe considered a medicationerror because the nurse didnot administer the medica-tion using the right route.The patient could suffererosion of the esophagus orstomach resulting in ableeding ulcer. Aspirin isan example of a medicationthat is enteric-coated toprevent erosion of gastro -intestinal tissue.


Capsules are usually of the time-release type, and these should never be crushedor opened because the medication would be immediately released into the system,instead of being released slowly over time.



Opening capsules andadding the medication toapplesauce or puddingwould also be considered amedication error becausethe nurse did not adminis-ter the medication usingthe right route. The patientcould receive an incorrectdosage of the medication asthe medication quicklyenters the gastrointestinalsystem.

Tablets: note scored tablet onright.

Caplets: note scored caplet onright.

Enteric-coated caplets.

Capsules. Controlled-release capsules.

Liquid medication is accurately administered using a medication cup or med-ication syringe. The medication cup contains the common equivalents for the met-ric, apothecary, and household systems to permit adaptation of the medication’sdosage for administration under various circumstances. The medication syringe con-tains the common equivalents for the metric and household systems to allow admin-istration of liquid medications to infants, elderly, or anyone experiencing difficultyswallowing.

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

Medication cup

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY

Medication syringe



E X A M P L E 4 . 9

Order: Cimetidine HCl 600 mg PO bid for gastrointestinal (GI) bleeding.

How many tsp will you give? _____________

Given quantity � 600 mgWanted quantity � tspDose on hand � 300 mg/5 mL

Sequential method:

2 tsp is the wanted quantity and the answer to the problem.

CIMETIDINE HCI LIQUID

8 fl oz (237 mL)

300 mg/5 mL Store between 15° and 30°C(59° and 86°F).Dispense in a tight, light-resistantcontainer. Each 5 mL (1 teaspoonful)contains cimetidine hydrochlorideequivalent to cimetidine, 300 mg;alcohol, 2.8%.Dosage: See accompanyingprescribing information.Important: Use safety closureswhen dispensing this productunless otherwise directed byphysician or requested bypurchaser.Caution: Federal law prohibitsdispensing without prescription.

LOT

6936

30-F

EX

P.

600 mg 5 mL tsp 6 × 5 30� 2 tsp

300 mg 5 mL 3 × 5 15

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12



E X A M P L E 4 . 1 0

Order: Prochlorperazine 10 mg PO qid for psychomotor agitation.

How many mL will you give? _____________

Given quantity � 10 mgWanted quantity � mLDose on hand � 5 mg/5 mL

Sequential method:


PROCHLORPERAZINE

as the edisylate SYRUP

4 fl oz (118 mL)

5 mg/5 mLStore at controlled room temperature(59° and 86°F).Dispense in a tight, light-resistantglass bottle.Each 5 mL (1 teaspoon) containsprochlorperazine, 5 mg, as theedisylate.Usual Dosage: Children: 5 to 15 mgdaily. Adults: 10 to 30 mg daily. Seeaccompanying folder for completeprescribing information.Important: Use child-resistantclosures when dispensing this productunless otherwise directed by physicianor requested by purchaser.Caution: Federal law prohibitsdispensing without prescription.

LOT

6927

78-V

EX

P.

10 mg 5 mL 10� 10 mL

5 mg

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12



E X A M P L E 4 . 1 1

Order: Tegretol 100 mg PO qid for convulsions.

How many tsp will you give? _____________

Given quantity � 100 mgWanted quantity � tspDose on hand � 100 mg/5 mL

Random method:

1 tsp is the wanted quantity and the answer to the problem.

Courtesy of Basel Pharmaceuticals.

100 mg 1 tsp 5 mL 1� 1 tsp

5 mL 100 mg

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY



Exercise 4.6 Administering Enteral Medications


1. Order: phenobarbital gr 1⁄2 PO daily for convulsions

On hand: 20 mg/5 mL

How many mL will you give? ________________

2. Order: Zantac 0.15 g PO bid for ulcers

On hand: 15 mg/mL

How many tsp will you give? ________________

3. Order: Dilaudid 3 mg PO every 3 hours prn for pain

On hand: Dilaudid Liquid 1 mg/mL


▲▲

▲

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY



Parenteral MedicationsMedications may also be ordered by the physician for the parenteral route of admin-istration, including subcutaneous (SQ), intramuscular (IM), and intravenous (IV).Parenteral medications are sterile solutions obtained from vials or ampules and areadministered using a syringe or prefilled syringes. The three syringes most oftenused are:

1. 3-mL syringe (used for a variety of medications requiring administration ofdoses from 0.2 to 3 mL).


4. Order: lactulose 20 g PO tid for hepatic encephalopathy

On hand: lactulose 10 g/15 mL

How many oz will you give? ________________

▲

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12

B

AA

0.5-mL low-dose syringe

1-mL syringe

3-mL syringe

2. Insulin syringe (used specifically to administer insulin). Two types are illustrated below A. 0.5-mL low-dose syringe for U-100 insulin and B. 1-mL syringe for U-100 insulin.


It is the responsibility of thenurse to choose the correctsyringe when administering parenteral medications. Thenurse can prevent medica-tion errors by being knowl-edgeable about differenttypes of syringes and whenit is appropriate to use spe-cific syringes.

Insulin is manufactured indifferent strengths and avariety of types based ononset, peak, and duration.Lilly and Novo Nordisk arethe primary providers ofinsulin. Insulin is classifiedas rapid acting (Humalogand Novolog), short-acting(Regular Insulin), interme-diate (NPH and Lente), andlong-acting (Lantus, andUltralente). Some types ofinsulin must be adminis-tered in a single syringe,and other types of insulincan be mixed in a singlesyringe for administration.

Insulin is given with aninsulin syringe that requiresno calculation. The numberof units of insulin orderedby the physician equals thenumber of units that thenurse draws using the correct insulin syringe: low-dose or regular U-100.

It is the responsibility ofthe nurse to be familiarwith the different types ofinsulin and to use a nurs-ing drug reference to pre-vent medication errorsassociated with insulinadministration. Everynurse should know theonset, peak, and durationof the insulin being admin-istered as well as the signsand symptoms of hypo-glycemia (pale, cool,clammy skin and hunger)and hyperglycemia (hot,red, dry skin and thirst).


3. Tuberculin syringe (used for a variety of medications requiring administrationof doses from 0.1 to 1 mL). Marked in hundredths to allow for rounding orexact dosage (eg, 0.75 mL).


Tuberculin syringe

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL


The nurse needs to befamiliar with the differenttypes of anticoagulants(heparin, Warfarin, andCoumadin) to ensurepatient safety and preventmedication errors. Thenurse needs to know whichlaboratory value to monitor(PT, PTT, INR) and whichantidote (protamine sulfateor vitamin K) to have avail-able for emergencies.

Heparin is an anticoagu-lant that is used to decreasethe clotting ability of theblood and help preventharmful clots from formingin the blood vessels.Although heparin is com-monly referred to as ablood thinner, it does notdissolve blood clots thathave already formed.Heparin may help preventblood clots from becominglarger and causing moreserious problems to theheart or lungs.

Heparin is administeredusing a tuberculin syringe,which is calibrated from0.1 to 1 mL. This allows formore accurate administra-tion of medication dosagesof less than 1 mL.

E X A M P L E 4 . 1 2

Order: Trimethobenzamide 100 mg IM qid for nausea.


Given quantity � 100 mgWanted quantity � mLDose on hand � 100 mg/mL

Sequential method:


TRIMETHOBENZAMIDE HCI

NOT FOR USE IN CHILDREN

For IM USE ONLY

20mL Multi-Dose Vial

100 mg/mL

Store between 15° and 30°C(59° and 86°F).Each mL of solution contains100 mg trimethobenzamidehydrochloride compounded with0.45% phenol as preservative,0.5 mg sodium citrateand 0.2 mg citric acid asbuffers, and sodium hydroxideto adjust pH to approximately 5.0.Dosage: See accompanyingprescribing information.Caution: Federal law prohibitsdispensing without prescription.For IM use only (preferably bydeep IM injection).

LOT

EX

P.

100 mg mL 1� 1 mL

100 mg 1

3 mL



E X A M P L E 4 . 1 3

Order: Prochlorperazine 10 mg IM every 4 hours for psychoses.


Given quantity � 10 mgWanted quantity � mLDose on hand � 5 mg/mL

Sequential method:


PROCHLORPERAZINE

as the edisylate INJECTION


5 mg/mL

Store below 86°F. Do not freeze.Protect from light. Discard ifmarkedly discolored.Each mL contains, in aqueoussolution, prochlorperazine,5 mg, as the edisylate;sodium biphosphate, 5 mg;sodium tartrate, 12 mg; sodiumsaccharin, 0.9 mg; benzylalcohol, 0.75%, as preservative.Dosage: For deep I.M. or I.V.injection. See accompanyingprescribing information.Caution: Federal law prohibitsdispensing without prescription.

LOT

EX

P.

3 mL

10 mg mL 10� 2 mL

5 mg 5

E X A M P L E 4 . 1 4

Order: morphine sulfate, 1–4 gr every 4 hours prn for pain.


Given quantity � 1_4 gr

Wanted quantity � mLDose on hand � 8 mg/mL or 1_8 gr/mL

Courtesy of Astra Pharmaceutical Products.



Random method:

1.87 mL is the wanted quantity and the answer to the problem, but, by using the

rounding rule, 1.9 mL would be given.

1_4 gr mL 60 mg 1_

4 × 60_1

60_4 15

� 1.87 mL or 1.9 mL8 mg 1 gr 8 × 1 8 8

3 mL

E X A M P L E 4 . 1 5

Order: NPH human insulin 20 units SQ every AM for type 1 diabetes mellitus.

How many units will you give? _____________

Sequential method:

20 units is the wanted quantity and the answer to the problem.

20 units� 20 units

Courtesy of Novo Nordisk Pharmaceutical.

mL




Courtesy of Novo Nordisk Pharmaceutical.

mL

E X A M P L E 4 . 1 7

Order: heparin 5000 units SQ bid for prevention of thrombi. On hand: heparin 10,000 units/mL.


Sequential method:

0.5 mL is the wanted quantity and the answer to the problem.

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

5000 units mL 5� 0.5 mL

10,000 units 10

E X A M P L E 4 . 1 6

Order: NPH human insulin 45 units SQ every AM for type 1 diabetes mellitus.

How many units will you give? _____________

Sequential method:



Exercise 4.7 Administering Parenteral Medications


1. Order: atropine sulfate 300 mcg IM for preoperative medication.


2. Order: hydromorphone 3 mg IM every 4 hours for pain.


▲▲

3 mL

3 mL






3. Order: meperidine 35 mg IV every hour for pain.


4. Order: regular insulin 10 units subcut every am for type 1 diabetes mellitus.

On hand: regular insulin 100 units/mL.

How many units will you give? ________________

5. Order: heparin 8000 units subcut bid for prevention of thrombi.

On hand: heparin 10,000 units/mL.


▲▲

▲

1 2 3 4 5 6 7 8 9

10m

L

Courtesy of Baxter Pharmaceuticals.

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL



Summary

This chapter has taught you to interpret medication orders and drug labels and tocalculate one-factor medication problems using dimensional analysis. To demon-strate your ability to interpret correctly and calculate accurately, complete the fol-lowing practice problems.

Practice Problems for Chapter 4 One-Factor Medication

Problems


1. The physician orders Tigan 0.2 g IM qid for nausea. The dosage of medica-

tion on hand is a multiple-dose vial labeled 100 mg/mL.

❊ How many mL will you give? _____________

2. A physician orders Thorazine 50 mg tid prn for singultus. The dose on hand

is Thorazine 25-mg tablets.

❊ How many tablets will you give? _____________

3. Order: Orinase 1 g PO bid for type 2 diabetes mellitus


3 mL





4. Order: Persantine 50 mg PO qid for prevention of thromboembolism


5. Order: NPH insulin 56 units SQ every AM for type 1 diabetes mellitus On

hand: NPH insulin 100 units/mL

❊ How many units will you give? _____________

6. Order: heparin 7500 units SQ bid for prevention of thrombi

On hand: heparin 10,000 units/mL


Courtesy of Boehringer Ingelheim Pharmaceuticals.

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL


7. Order: Amoxicillin/clavulanate potassium 500 mg PO every 8 hours for infection.


8. Order: Zaroxolyn 5 mg PO every AM for hypertension



AMOXICILLIN/

CLAVULANATE POTASSIUM

FOR ORAL SUSPENSION

When reconstituted, each 5 mL contains:AMOXICILLIN, 125 MG,as the trihydrateCLAVULANIC ACID, 31.25 MG,as clavulanate potassium

125 mg/5mL Tear along perforation

Directions for mixing;Tap bottle until all powder flowsfreely. Add approximately 2/3 oftotal water for reconstitution(total = 67 mL); shakevigorously to wet powder. Addremaining water; again shakevigorously.Dosage: See accompanyingprescribing information.

Tear along perforation

Keep tightly closed.

Shake well before using.

Must be refrigerated.

Discard after 10 days.

Use

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ct.

Net

co

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: Equ

ival

ent t

o1.

875

g am

oxic

illin

and

0.46

9 g

clav

ulan

ic a

cid.

Sto

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roo

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31

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12

Courtesy of Fisons Pharmaceuticals.



1 0 0 S E C T I O N 1 Clinical Calculations

9. Order: methylphenidate (Ritalin) 10 mg PO tid for attention-deficit

hyperactivity disorder (ADHD)


10. Order: meperidine 50 mg IM every 3 hours prn for pain.

On hand: meperidine 100 mg/mL


11. Order: Cinacalcet hydrochloride (Sensipar) 60 mg PO bid for secondary

hyperparathyroidism.

On hand: Sensipar 30 mg tablets

❊ How many tablets will you give?

12. Order: Diltiazem hydrochloride (Cardizem) 120 mg PO bid for angina pec-

toris due to coronary artery spasm.

On hand: Cardizem 60 mg tablets


13. Order: Gemfibrozil (Lopid) 600 mg PO bid 30 minutes AC for hyperlipidemia.

On hand: Lopid 600 mg tablets


14. Order: Enoxaparin (Lovenox) 30 mg SQ daily for prophylaxis for DVT after

total knee replacement.

On hand: Lovenox 60 mg/0.6 mL


Courtesy of Medeva Pharmaceuticals.

3 mL


15. Order: Amlodipine (Norvasc) 10 mg PO daily for hypertension.

On hand: Norvasc 2.5 mg/tablet


16. Order: Calcium carbonate (Os-Cal) 1.25 g PO daily for mild hypocalcemia.

On hand: Os-Cal 1250 mg capsules


17. Order: Tamsulosin hydrochloride (Flomax) 0.8 mg PO daily PC for benign

prostatic hypertrophy.

On hand: Flomax 0.4 mg capsules


18. Order: Ropinirole hydrochloride (Requip) 1.5 mg PO daily for Parkinson’s

disease.

On hand: Requip 0.5 mg tablets


19. Order: Lisinopril (Prinivil) 5 mg PO daily for hypertension.

On hand: Prinivil 2.5 mg tablets


20. Order: Metformin hydrochloride (Glucophage) 1000 mg PO daily for type 2

diabetes.

On hand: Glucophage 500 mg tablets


CHAPTER 4 One-Factor Medicat ion Problems 1 0 1



Chapter 4 Post-Test One-Factor Medication

Problems

Name Date

1. Order: Micronase 1.25 mg PO daily for non-insulin-dependent diabetes

mellitus


2. Order: Tegretol 50 mg PO qid for seizures


Courtesy of Basel Pharmaceuticals.


(Post-Test continues on page 104)


3. Order: acetaminophen 240 mg PO every 4 hours prn for moderate pain

❊ How many milliliters will you give? _____________

4. Order: lactulose 30 g PO qid for hepatic encephalopathy


1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY

Courtesy of Roxane Laboratories, Inc.


2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12





5. Order: Cimetidine HCl 300 mg PO qid for short-term treatment of active ulcers

❊ How many teaspoons will you give? _____________

6. Order: Trimethobenzamide HCl 0.2 g IM tid prn for nausea



Single-Dose Unit

300 mg/5mL

Each 5 mL dose containscimetidine hydrochlorideequivalent to cimetidine,300 mg; alcohol, 2.8%.Caution: Federal lawprohibits dispensingwithout prescription.

LOT EXP.

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12



FOR IM USE ONLY


100 mg/mL

Store at controlled roomtemperature (15° to 30°C; 59°to 86°F). Each mL of solutioncontains 100 mg trimethobenzamidehydrochloride compoundedwith 0.45% phenol aspreservative, 0.5 mgsodium citrate and 0.2mg citric acid as buffers,and sodium hydroxide toadjust pH to approximately5.0.Dosage: See accompanyingprescribing information.Caution: Federal lawprohibits dispensing withoutprescription. For IM use only(preferably by deep IM injection).

LOT

EX

P.


7. Order: hydromorphone 3 mg IM every 3 hours for pain


8. Order: magnesium sulfate 1000 mg IM in each buttock for hypomagnesemia







9. Order: naloxone HCl 200 mcg IV stat for respiratory depression


10. Order: Solu-Medrol 40 mg IM daily for autoimmune disorder


Courtesy of Astra PharmaceuticalProducts.




Exercise 4.1 Interpretation of

Medication Orders

1

a. Right patient Mrs. A. Clarkb. Right drug Aspirin for feverc. Right dosage gr 10d. Right route orally (PO)e. Right time every 4 hr as needed (prn)f. Right documentation: The patient’s name, the

drug, the dosage, the route administered and thedate and time administered should be charted onthe Medication Administration Record (MAR).Aspirin is a prn medication and therefore the rea-son the drug was administered and the effects fol-lowing administration of the drug should also becharted on the MAR. The nurse’s signature and ini-tials should appear on the MAR.

2

a. Right patient Mr. W. Smithb. Right drug Advil (ibuprofen) for arthritisc. Right dosage 400 mgd. Right route PO (orally)e. Right time every 6 hrf. Right documentation: The patient’s name, the drug,

the dosage, the route administered and the date andtime administered should be charted on the Medica-tion Administration Record (MAR). Advil is a regu-larly scheduled medication and the reason for thedrug administration is listed as arthritis. The nurse’ssignature and initials should appear on the MAR.

3

a. Right patient Mr. T. Jonesb. Right drug Tylenol (acetaminophen) for

headachec. Right dosage gr 10d. Right route PO (orally)e. Right time every 4 hr prnf. Right documentation: The patient’s name, the drug,

the dosage, the route administered and the date andtime administered should be charted on the Medica-tion Administration Record (MAR). Tylenol is a prnmedication and therefore the reason the drug wasadministered and the effects following administra-tion of the drug should also be charted. The nurse’ssignature and initials should appear on the MAR.

Exercise 4.3 One-Factor Medication

Problems

1

Sequential method:

Random method:

2

Sequential method:

Random method:

3

Sequential method:

Random method:

4

Sequential method:

Random method:

0.25 g 1000 mg capsule 0.25 × 100 25� 1 capsule

1 g 250 mg 1 × 25 25

0.25 g capsule 1000 mg 0.25 × 100 25� 1 capsule

250 mg 1 g 25 × 1 25

1_2 gr 60 mg tablet 1_

2 × 60_1

60_2 30

� 2 tablets1 gr 15 mg 1 × 15 15 15

1_2 gr tablet 60 mg 1_

2 × 60_1

60_2 30

� 2 tablets15 mg 1 gr 15 × 1 15 15

0.5 g 1000 mg tablet 0.5 × 10 5� 1 tablet

1 g 500 mg 1 × 5 5

0.5 g tablet 1000 mg 0.5 × 10 5� 1 tablet

500 mg 1 g 5 × 1 5

0.03 g 1000 mg capsules 0.03 × 100 3� 1 capsule

1 g 30 mg 1 × 3 3

0.03 g capsules 1000 mg 0.03 × 100 3� 1 capsule

30 mg 1 g 3 × 1 3

ANSWER KEY FOR CHAPTER 4: ONE-FACTOR MEDICATION PROBLEMS



5

Sequential method:

Random method:

Exercise 4.4 Identifying the

Components of

Drug Labels

1

a. Ciprob. Ciprofloxacin hydrochloridec. 500 mg per tabletd. 100 tabletse. *Not listed on the labelf. *Not listed on the labelg. Bayer Corporation, Pharmaceutical Division

2

a. Zoviraxb. acyclovirc. 400 mg per capsuled. 100 tabletse. *Not listed on the labelf. *Not listed on the labelg. GlaxoSmithKline

3

a. Halcionb. Triazolamc. 0.125 mg per tabletd. 10 tabletse. *Not listed on the labelf. *Not listed on the labelg. The Upjohn Company

Exercise 4.5 Problems With

Components

of Drug Labels

1

Sequential method:

1_2 gr 60 mg capsules 1_

2 × 60_1

60_2 30

� 1 capsule1 gr 30 mg 1 × 30 30 30

1_2 gr capsules 60 mg 1_

2 × 60_1

60_2 30

� 1 capsule30 mg 1 gr 30 × 1 30 30

10 mg tablet 10� 1 tablet

10 mg 10

500 mcg tablet 1 mg 51 mg 1000 mcg 10

375 mg tablet 375250 mg 250

� 11_2

tablets

2.5 mg tablet 1000 mcg 2.5 × 10 25� 1 tablet

2500 mcg 1 mg 25 × 1 25

250 mg capsule 25 � 1 capsule

250 mg 25

� 1_2

tablet

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

1_2 gr 5 mL 60 mg 1_

2 × 5_1 × 6_

130_2 15

� 7.5 mL20 mg 1 gr 2 × 1 2 2

0.15 g 1000 mg mL 1 tsp 0.15 × 1000 150� 2 tsp

1 g 15 mg 5 mL 15 × 5 75

2

Random method:

3

Sequential method:

4

Random method:

5

Sequential method:

Exercise 4.6 Administering Enteral

Medications

1

Random method:

2

Sequential method:



3

Sequential method:

4

Sequential method:

5

Sequential method:

Practice Problems

1

Random method:

2

Sequential method:

3

Sequential method:

4

Sequential method:

Exercise 4.7 Administering Parenteral

Medications

1

Random method:

2

Sequential method:

3 mg mL 3� 3 mL

1 mg 11

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

20 g 15 mL 1 oz 2 × 15 × 1 30� 1 oz

10 g 30 mL 1 × 30 30

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

300 mcg mL 1 mg 3 × 1 3� 3 mL

0.1 mg 1000 mcg 0.1 × 10 1

3 mL

3 mL

3 mg mL 3� 1.5 mL

2 mg 2

1 2 3 4 5 6 7 8 9

10m

L

35 mg mL 35� 3.5 mL

10 mg 10


mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

3 mL

8000 units mL 8� 0.8 mL

10,000 units 10

0.2 g mL 1000 mg 0.2 × 10 2 � 2 mL

100 mg 1 g 1 × 1 1

50 mg tablet 50 � 2 tablets

25 mg 25



9

Sequential method:

10

Sequential method:

11

12

13

14

15

Nursing action: Contact the pharmacy to checkwhether there is a different dosage so that fourtablets would not have to be given. Tablets are available as 5 mg and 10 mg tablets.


25 mg 25

mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL


7500 units mL 75 � 0.75 mL

10000 units 100

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

500 mg 5 mL 500 × 5 2500� 20 mL

125 mg 125 125

3

Random method:

4

Random method:

5

Sequential method:

6

Sequential method:

7

Sequential method:

8

Sequential method:

5 mg tablet 5 � 2 tablets

2.5 mg 2.5


5 mg 5

50 mg mL 5 � 0.5 mL

100 mg 10

mL


30 mg 3


60 mg 6


600 mg 6

30 mg 0.6 mL 3 × 0.6 1.8� 0.3 mL

60 mg 6 6


2.5 mg 2.5

1 g tablet 1000 mg 1 × 10 10� 2 tablets

500 mg 1 g 5 × 1 5



16

17

18

Nursing action: Contact the pharmacy to checkwhether there is a different dosage so that threetablets would not have to be given. Tablets are available as 1 mg tablets.

19

20

1.5 mg tablets 1.5� 3 tablets

0.5 mg 0.5

5 mg tablets 5� 2 tablets

2.5 mg 2.5


500 mg 5


1250 mg 1 g 125 × 1 125

0.8 mg capsule 0.8� 2 capsules

0.4 mg 0.4


C H A P T E R 5Two-Factor Medication Problems

Objectives


1. Solve two-factor–given quantity to one-factor–wanted quantity medication problemsinvolving a specific amount of medicationordered based on the weight of the patient.

2. Calculate medication problems requiringreconstitution of medications by usinginformation from a nursing drug reference,label, or package insert.

3. Solve two-factor–given quantity to two-factor– wanted quantity medication problemsinvolving a specific amount of fluid to be deli -vered over limited time using an intravenouspump delivering milliliters per hour (mL/hr).

4. Solve two-factor–given quantity to two-factor–w anted quantity medication problemsinvolving a specific amount of fluid to bedelivered over a limited time using differenttypes of intravenous tubing that deliver dropsper minute (gtt/min) based on a specific drop factor.

A lthough medications are ordered by physicians ornurse practitioners and administered by nurses using

the “six rights of medication administration,” other factorsmust be considered when administering certain medicationsor intravenous (IV) fluids.

Outline

MEDICATION PROBLEMS INVOLVING WEIGHT 115Exercise 5.1: Pediatric Medication Problems

Involving Weight 117

MEDICATION PROBLEMS INVOLVING RECONSTITUTION 119

Exercise 5.2: Medication Problems

Involving Reconstitution 123

MEDICATION PROBLEMS INVOLVING INTRAVENOUS PUMPS 124

Exercise 5.3: Medication Problems Involving

Intravenous Pumps 127

MEDICATION PROBLEMS INVOLVING DROP FACTORS 128

Exercise 5.4: Medication Problems Involving Drop

Factors 132

MEDICATION PROBLEMS INVOLVING INTERMITTENT INFUSION 132

Exercise 5.5: Medication Problems Involving

Intermittent Infusion 134

Practice Problems for Chapter 5: Two-Factor Medication Problems 136

Post-Test for Chapter 5: Two-Factor Medication Problems 141

Answer Key for Chapter 5: Two-Factor Medication Problems 147

1 1 4



CHAPTER 5 Two-Factor Medicat ion Problems 1 1 5

The weight of the patient often must be factored into a medication prob-lem when determining how much medication can safely be given to an infantor a child or an elderly patient.

The dosage of medication available may be in a powdered form that needsreconstitution to a liquid form before parenteral or IV administration.

Also, the length of time over which medication or IV fluids can be givenplays an important role in the safe administration of IV therapy.

To be able to calculate a two-factor–given quantity to one-factor– or two-factor–wanted quantity medication problem, it is important to understand all factorsthat may need to be considered in some medication problems. With use ofdimensional analysis, this chapter will teach you to calculate medication prob-lems involving the weight of the patient, the reconstitution of medications frompowder to liquid form, and the amount of time over which medications or IVfluids can be safely administered.

E X A M P L E 5 . 1

The physician orders gentamicin 2.5 mg/kg IV (intravenous) every 8 hoursfor infection. The vial of medication is labeled 40 mg/mL. The childweighs 60 lb.

How many milliliters will you give? _____________

Given quantity = 2.5 mg/kgWanted quantity = mLDose on hand = 40 mg/mLWeight = 60 lb

Thin kingit

ThroughThe two-factor–given quan-tity has been set up with anumerator (2.5 mg) and adenominator (kg) leadingacross the unit path to aone-factor– wanted quantitywith only a numerator (mL).

The dose on hand(40 mg/mL) has been fac-tored in to cancel out thepreceding unwanted unit(mg). The wanted unit (mL)is in the numerator and corresponds with the one-factor–wanted quantity (mL).

Unit Path

Conversion Factor Conversion Factor for Given Quantity for Given Quantity ConversionGiven Quantity (Numerator) (Denominator) Computation Wanted Quantity

2.5 mg mL 1 kg 60 lb 2.5 × 1 × 6 15

kg 40 mg 2.2 lb 4.22 8.8 � 1.7 mL

6 744444 844444

MEDICATION PROBLEMS INVOLVING WEIGHT

When solving problems with dimensional analysis, you can use either the sequen-tial method or the random method to calculate two-factor–given quantity med-ication problems. The given quantity (the physician’s order) contains two partsincluding a numerator (dosage of medication) and a denominator (the weight ofthe patient). This type of medication problem is called a two-factor medicationproblem because the given quantity now contains two parts (a numerator and adenominator) instead of just one part (a numerator).

Below is an example of the problem-solving method showing placement of basicterms used in dimensional analysis, applied to a two-factor medication probleminvolving weight.

(Example continues on page 116)(Thinking it Through continues on page 116)



Sequential method:

Step 1 Identify the two-factor–given quantity (the physician’s order).

Step 2

Step 3

Step 4

A conversion factor(1 kg � 2.2 lb) is factoredinto the unit path to cancelout the preceding unwantedunit (kg).

The weight is finally fac-tored in to cancel out thepreceding un wanted unit (lb)in the denominator. Allunwanted units are can celedand only the wanted unit (mL)remains and correspondswith the wanted quantity(mL). Multiply the numera-tors, multiply the denomina-tors, and divide the productof the numerators by theproduct of the denominatorsto provide the numericalvalue.

Unit Path


2.5 mg

kg � mL

Unit Path


2.5 mg mL

kg 40 mg � mL

Unit Path


2.5 mg mL

kg 40 mg � mL

2.2 lb

1 kg

Unit Path


2.5 mg mL

kg 40 mg � mL

2.2 lb

1 kg 60 lb

6 744444 844444

6 744444 844444

6 744444 844444

6 744444 844444


One of the most frequentmedication errors is theerror made with the con-version of weight.

The weight conversion [1 kg � 2.2 lb] is oftenincorrectly written [1 lb �2.2 kg].

Remember that youwould rather tell someoneyour weight in kilogramsas it is a much smallernumber [1 kg � 2.2 lb or,put in more realistic terms,90.9 kg � 200 lb].


Step 5

Dimensional analysis is a problem-solving method that uses critical think-ing. When implementing the random method of dimensional analysis,the medication problem can be set up in a number of different ways. Thefocus is on the correct placement of conversion factors to cancel out allunwanted units. The wanted unit is placed in the numerator to correctlycorrespond with the wanted quantity.

2.5 mg 1 kg 60 lb mL 2.5 × 1 × 6 15

kg 2.2 lb 40 mg 2.2 × 4 8.8 � 1.7 mL

Unit Path


2.5 mg mL

kg 40 mg � 1.7 mL

2.2 lb

1 kg 60 lb 2.5 × 1 × 6 15

4 × 2.2 8.8


6 744444 844444

Exercise 5.1 Pediatric Medication Problems Involving Weight


1. Order: furosemide 1 mg/kg IV bid for hypercalcemia. The child weighs

45 lb.



3 mL

▲





2. Order: atropine sulfate 0.01 mg/kg IV stat for bradycardia. The child weighs

20 lb.



3. Order: phenergan 0.5 mg/kg IV every 4 hours prn for nausea. The dose on

hand is 25 mg/mL. The child weighs 45 lb.


4. Order: morphine 50 mcg/kg IV every 4 hours prn for pain. The child weighs

75 lb.



.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

▲▲

▲


5. Order: Cimetidine HCl 10 mg/kg PO qid for prophylaxis of duodenal ulcer.The dose on hand is 300 mg/5 mL. The child weighs 70 lb.


▲

CIMETIDINE HCI

LIQUID

8 fl oz (237 mL)

300 mg/5mL Store between 15° and 30°C(59° and 86°F). Dispense in atight, light-resistant container.Each 5 mL (1 teaspoonful)contains cimetidine hydrochlorideequivalent to cimetidine,300 mg; alcohol, 2.8%.Dosage: See accompanyingprescribing information.Important: Use safety closureswhen dispensing this productunless otherwise directed byphysician or requested bypurchaser.Caution: Federal law prohibitsdispensing without prescription.

LOT

EX

P.

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12


When reconstituting med-ication, always check anursing drug reference toobtain information regard-ing the correct diluents andthe correct amount of thediluents to be used to pre-vent medication errors.

MEDICATION PROBLEMSINVOLVING RECONSTITUTION

Some medications in vials are in a powder form and need reconstitution beforeadministration. Reconstitution involves adding a specific amount of sterile solution(also called diluent) to the vial to change the powder to a liquid form. Informationon how much diluent to add to the vial and what dosage of medication per milliliterwill result after reconstitution (also called yield) can be obtained from a nursing drugreference, label, or package insert.




E X A M P L E 5 . 2

The physician orders Mezlin (mezlocillin) 50 mg/kg every 4 hours IV forinfection. The child weighs 60 lb. The pharmacy sends a vial of medica-tion labeled Mezlin 1 g. The nursing drug reference provides informationto reconstitute 1 g of medication with 10 mL of sterile water for injection, 0.9% NaCl, or D5W.

How many milliliters will you draw from the vial? _____________

Given quantity = 50 mg/kgWanted quantity = mLDose on hand = 1 g/10 mL (yields 1 g/10 mL)Weight = 60 lb

Random method:

13.63 mL or 13.6 mL is the wanted quantity and the answer to the problem.

5 10 15

20m

L

Unit Path

Conversion Factor Conversion Factor Given for Given Quantity for Given Quantity Conversion Quantity (Numerator) (Denominator) Computation Wanted Quantity

�

10 mL1 kg50 mg

kg 2.2 lb

1 g 5 × 1 × 6 × 1 30

2.22.2 × 11000 mg1 g

60 lb 13.63 mLor 13.6 mL

6 744444 844444


E X A M P L E 5 . 3

Order: Solu-Medrol 40 mg IV every 4 hours for inflammation.

How many milliliters will you draw from the vial? ____________


Given quantity � 40 mgWanted quantity � mLDose on hand � 125 mg/2 mL (yield from 2 mL Act-O-Vial)





Sequential method:

40 mg

125 mg 125 125� 0.64 mL or 0.6 mL

2 mL 40 × 2 80


.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

E X A M P L E 5 . 4

Order: Claforan 50 mg/kg IV every 8 hours for infection. The infant weighs12 kg.

How many milliliters will you draw from the vial after reconstitution? _____________

Courtesy of Hoechst-Roussel Pharmaceuticals.

Supply: Claforan 1 g/10 mLThe package insert states: Reconstitute vials with at least 10 mL of sterilewater for injection.

Given quantity � 50 mg/kgWanted quantity � mLDose on hand � 1 g/10 mLWeight � 12 kg


Random method:


1 2 3 4 5 6 7 8 9

10m

L

50 mg

1 gkg 1000 mg 1 × 10 10

10 mL 1 g 12 kg 5 × 1 × 1 × 12 60� 6 mL

Exercise 5.2 Medication Problems Involving Reconstitution


1. Order: cefazolin 500 mg IV every 8 hours for infection.

How many milliliters will you draw out of the vial after reconstitution? _____________

(Cefazolin is reconstituted using 50 mL sodium chloride.)

2. Order: Primaxin 250 mg IV every 6 hours for infection

Supply: Primaxin vial labeled 500 mg. Reconstitute with 10 mL of compatible

diluent and shake well.


STERILE CEFAZOLIN

SODIUM (LYOPHILIZED)

STERILE CEFAZOLIN

equivalent to 1 gram cefazolinSODIUM (LYOPHILIZED)

“Piggyback” Vial for

Intravenous Admixture

equivalent to

1 gram cefazolin

Before reconstitution protect from light andstore at controlled room temperature15° to 30°C (59° to 86°F).Primarily for institutional use. Each vialcontains cefazolin sodium equivalent to 1gram of cefazolin. The sodium content is46 mg per gram of cefazolin.Usual Adult Dosage: Dilute with 50 to100 mL of Sodium Chloride Injection orother intravenous solution listed inaccompanying prescribing information.SHAKE WELL. Administer as single dosewith primary intravenous fluids. ReconstitutedAncef is stable for 24 hours at room temperatureor for 10 days if refrigerated (5°C or 41°F).Caution: Federal law prohibitsdispensing without prescription.

LOT

EX

P.

▲▲





3. Order: Unasyn (ampicillin) 50 mg/kg IV every 4 hours for infection

Supply: Unasyn 1.5-g vial

Nursing drug reference: Reconstitute each Unasyn 1.5-g vial with 4 mL of

sterile water to yield 375 mg/mL.

The child weighs 40 kg.


4. Order: erythromycin 750 mg IV every 6 hours for infection

Supply: erythromycin 1-g vial labeled: Reconstitute with 20 mL of sterile

water for injection.


5. Order: Fortaz 30 mg/kg IV every 8 hours for infection

Supply: Fortaz 500-mg vial labeled: Reconstitute with 5 mL of sterile water

for injection

The child weighs 65 lb.


▲▲

▲

MEDICATION PROBLEMS INVOLVING INTRAVENOUS PUMPS

IV medications are administered by drawing a specific amount of medication from avial or ampule and inserting that medication into an existing IV line. All IV medica-tions must be given with specific thought to exactly how much time it should take toadminister the medication. Information regarding time may be obtained from a nurs-ing drug reference, label, or package insert, or may be specifically ordered by thephysician.

Although IV medications can be administered IV push, the time involved oftenrequires the use of an IV pump. All IV pumps deliver milliliters per hour (mL/hr) butmay vary in operational capacity or size.

Below is an example of the dimensional analysis problem-solving method withbasic terms applied to a medication problem involving an IV pump.

Unit Path

hr

250 mL 151500 Units� 15 mL

25,000 Units hr

Conversion Factorfor Given Quantity

(Numerator)Conversion

Computation Wanted QuantityGiven Quantity

6 744 844

67 448 44


When administering IVmedications and fluids,always check a nursingdrug reference to obtain thecorrect information regard-ing how much medicationor fluid can safely beadministered to preventmedication errors.

It is the responsibility ofthe nurse to be familiarwith the different types ofIV pumps that are used todeliver IV medications orfluids. All medicationsdelivered by the IV routeshould be delivered usingan IV pump to ensure accu-racy and safety of delivery.


E X A M P L E 5 . 5

The physician orders heparin 1500 units/hr IV. The pharmacy sends an IV bag labeled: Heparin 25,000 units in 250 mL of D5W.

Calculate the IV pump setting for milliliters per hour.

Given quantity = 1500 units/hrWanted quantity = mL/hrDose on hand = 25,000 units/250 mL

Sequential method:

Step 1 Begin by identifying the given quantity. Establish the unit path to thewanted quantity.

Step 2

Step 3

15 mL/hr is the wanted quantity and the answer to the problem.

Thin kingit

ThroughThe two-factor–given quan-tity (the physician’s order)contains a numerator (thedosage of medication) and adenominator (time). Thewanted quantity (the an swerto the problem) also con-tains a numerator (mL) and adenominator (time). This iscalled a two-factor–givenquantity to a two-factor–wanted quantity medicationproblem. The denominatorof the given quantity (hr)corresponds with thedenominator of the wantedquantity (hr); therefore, onlythe numerator of the givenquantity (units) needs to becanceled from the problem.

After factoring in the doseon hand, the unwanted unit(units) is canceled from theproblem and the wanted unit(mL) remains in the numera-tor to correspond with thewanted quantity. The samenumber values are canceledfrom the numerator anddenominator, leaving 15 mL/hr.

1500 Units mL

hr hr�




Unit Path6 744 844

1500 Units 250 mL mL

hr 25,000 Units hr�




Unit Path6 744 844

1500 Units 250 mL 15 15 mL

hr 25,000 Units hr�




Unit Path6 744 844




E X A M P L E 5 . 6

The physician orders 500 mL of 0.45% NS with 20 mEq of KCl to infuseover 8 hours.

Calculate the number of milliliters per hour to set the IV pump.

Given quantity = 500 mL/8 hrWanted quantity = mL/hr

Sequential method:


500 mL

8 hror

8 hr�

500 62.5 mL 63 mL

E X A M P L E 5 . 7

The physician orders aminophylline 44 mg/hr IV. The pharmacy sends an IV bag labeled: Aminophylline 1 g/250 mL NS.

Calculate the milliliters per hour to set the IV pump.

Given quantity = 44 mg/hrWanted quantity = mL/hrDose on hand = 1 g/250 mL

Random method:


E X A M P L E 5 . 8

The nurse checks the IV pump and documents that the pump is set atand delivering 11 mL/hr and that the IV bag hanging is labeled: Amino-phylline 1 g/250 mL.

How many milligrams per hour is the patient receiving?

Given quantity = 11 mL/hrWanted quantity = mg/hrDose on hand = 1 g/250 mL

44 mg 250 mL 1 g 44 × 25 1100 11 mL

hr 1 g 1000 mg 100 100 hr�

Thin kingit

ThroughThe given quantity has beenidentified as what the physi-cian orders, but also can beinformation that the nursehas obtained. The nursemay know that the IV pumpis set to deliver 11 mL/hr,but wants to know if thedosage of medication thepatient is receiving is withina safe dosage range.

Thin kingit

ThroughIn this problem, the neededtwo factors are already iden-tified in the given quantity and, therefore, require noadditional conversions. The20 mEq of KCl added to theIV bag is included as part ofthe 500 mL and is additionalinformation for the nurse, butnot part of the calculation.

Thin kingit

ThroughThe dose on hand is fac-tored in and allows theunwanted unit (mL) to becanceled.


Sequential method:

Step 1

Step 2

Step 3

44 mg/hr is the wanted quantity and the answer to the problem.

11 mL

hr hr�

mg

11 mL 1 g

hr 250 mL hr�

mg

11 mL 1 g 1000 mg 11 × 100 1100

hr 250 mL 1 g 25 25 hr�

44 mg

Exercise 5.3 Medication Problems Involving

Intravenous Pumps


1. Order: heparin 1800 units/hr IV

Supply: heparin 25,000 units/250 mL D5W

Calculate the milliliters per hour to set the IV pump. _____________

2. Order: aminophylline 35 mg/hr IV

Supply: aminophylline 1 g/250 mL NS


3. Information obtained by the nurse: heparin 25,000 units in 250 mL D5W isinfusing at 30 mL/hr.

How many units per hour is the patient receiving? _____________

▲▲

▲





4. Information obtained by the nurse: aminophylline 1 g/250 mL NS is infus-ing at 15 mL/hr.

How many milligrams per hour is the patient receiving? _____________

5. Order: heparin 900 units/hr IV

Supply: heparin 25,000 units/500 mL D5W


▲▲

MEDICATION PROBLEMS INVOLVING DROP FACTORS

Although IV pumps are used whenever possible, there are situations (no IV pumpsavailable) and circumstances (outpatient or home care) that arise when IV pumpsare not available and IV fluids or medications might be administered using gravityflow. Gravity flow involves calculating the drops per minute (gtt/min) required toinfuse IV fluids or medications. When IV fluids or medications are administeredusing gravity flow, it is important to know the drop factor for the IV tubing that isbeing used. Drop factor is the drops per milliliter (gtt/mL) that the IV tubing willproduce. Two types of IV tubing are available for gravity flow. Macrotubing deliversa large drop and is available in 10 gtt/mL, 15 gtt/mL, and 20 gtt/mL (Table 5.1); andmicrotubing delivers a small drop and is available in 60 gtt/mL.

Regardless of the IV tubing used, the problem can be solved by dimensionalanalysis. Below is an example of a medication problem involving drop factors usingthe dimensional analysis method.

250 mL

30 min mL 3

10 gtt 250 × 1 250

3

83.3 gtt 83 gtt

min min� or




Unit Path6 744 844

TABLE 5.1 Examples of Different Macrodrip Factors

Travenol 10Abbott 15McGaw 15Cutter 20

Manufacturer Drops per milliliter (gtt/mL)


When IV fluids are admin-istered by gravity (withoutthe use of an IV pump), it is the responsibility of thenurse to investigate the history of each patient toensure safe delivery of IVfluids.

IV fluids that flow bygravity need to be moni-tored closely because theflow of the fluids canchange with the position ofthe hand or arm. Somepatients with a history ofcongestive heart failure donot tolerate large volumesof IV fluids.


E X A M P L E 5 . 9

The physician orders 250 mL of normal saline to infuse in 30 minutes. Thedrop factor listed on the IV tubing box is 10 gtt/mL.

Calculate the number of drops per minute required to infusethe IV bolus.

Given quantity = 250 mL/30 minWanted quantity = gtt/minDrop factor = 10 gtt/mL

Sequential method:

Step 1 Begin by identifying the given quantity and establishing a unit pathto the wanted quantity.

Step 2

Step 3

83 gtt is the wanted quantity and the answer to the problem.

Thin kingit

ThroughThe given quantity and thewanted quantity bothinclude two factors; there-fore, this is a two-factor–given quantity to a two-factor–wanted quantity medication problem.

The denominators are thesame (min). The numeratorin the given quantity (mL) isan unwanted unit and needsto be canceled.

When the drop factor isfactored in, the unwantedunit (mL) is canceled, andthe wanted unit (gtt) isplaced in the numerator tocorrespond with the wantedquantity.

After you cancel theunwanted units from theproblem, multiply thenumerators, multiply thedenominators, and dividethe product of the numera-tors by the product of thedenominators to provide thewanted quantity.

250 mL

30 min

gtt

min�




Unit Path6 744 844

250 mL 10 gtt

30 min mL

gtt

min�




Unit Path6 744 844

250 mL 10 gtt 250 × 1 250

30 min mL 3 3

83.3 gtt

min�




Unit Path6 744 844

83 gtt

minor




E X A M P L E 5 . 1 0

In some situations (home care), it may be important for the nurse to knowexactly how long a specific amount of IV fluid will take to infuse. Thephysician may order a limited amount of IV fluid to infuse at a specificnumber of drops per minute (gtt/min).

The physician orders 1000 mL of D5W and 0.45% NS to infuse over 8 hours. The drop factor is 20 gtt/mL.

Calculate the number of drops per minute required to infuse the IV volume.

Given quantity = 1000 mL/8 hrWanted quantity = gtt/minDrop factor = 20 gtt/mL

Sequential method:

Step 1

Step 2

Step 3

42 gtt/min is the wanted quantity and the answer to the problem.

Thin kingit

ThroughThe unwanted unit (mL) iscanceled, and the wantedunit (gtt) is placed in thenumerator. Anotherunwanted unit (hr) needs to be canceled from the unitpath.

The conversion factor (1 hr � 60 min) has been factored in to allow theunwanted unit (hr) to be canceled and the wanted unit (min) is placed in the denominator.

1000 mL

mL8 hr

20 gtt gtt

min�

1000 mL

mL 60 min8 hr

20 gtt 1 hr gtt

min�

1000 mL

mL 60 min 8 × 6 488 hr

20 gtt 1 hr 1000 × 2 × 1 2000 41.66 gtt

min�

or 41.66 gtt

min

42 gtt

min


E X A M P L E 5 . 1 1

It is safe nursing practice to monitor an infusing IV every 2 hours to makesure it is infusing without difficulty and on time. It may be necessary tohang the next IV after 71

2 hours (before the estimated completion time)to keep the IV from running dry.

The physician orders 1000 mL of D5W. The drop factor is 10 gtt/mL.The infusion is dripping at 21 gtt/min.

How many hours will it take for the IV to infuse?

Given quantity = 1000 mLWanted quantity = hrDrop factor = 10 gtt/mL

Step 1

Step 2

Step 3

Step 4

Step 5

8 hours is the wanted quantity and the answer to the problem.

Thin kingit

ThroughThe given quantity and thewanted quantity have beenidentified and are both inthe numerator; therefore,this is a one-factor–givenquantity to a one-factor–wanted quantity medicationproblem.

The drop factor (10 gtt/mL)has been factored in usingthe sequential method tocancel the unwanted unit(mL).

The infusing rate of 21 gtt/min has now been factored in to cancel theunwanted unit (gtt).

The conversion factor (1 hr � 60 min) has been factored in to cancel theunwanted unit (min). Thewanted unit (hr) remains in the numerator, which corresponds to the wantedquantity.

1000 mL� hr

1000 mL

mL� hr

10 gtt

1000 mL

mL 21 gtt� hr

10 gtt min

1000 mL

mL 21 gtt 60 min� hr

10 gtt min 1 hr

1000 mL

mL 21 gtt 60 min 21 × 6 126� 7.93 hr or 7.9 hr

10 gtt min 1 hr 1000 × 1 × 1 1000



It is the responsibility of thenurse to ensure that an IVdoes not run dry andendanger the patient due toair in the IV line.

Check an IV bag infusingby gravity every 1 to 2hours and/or instruct thepatient to report when theIV has only a small amount(100 mL) left in the IVbag.



Exercise 5.4 Medication Problems Involving Drop Factors


1. Order: 800 mL D5W to infuse in 8 hours

Drop factor: 15 gtt/mL

Calculate the number of drops per minute. _____________

2. Order: Infuse 250 mL NS


Infusion rate: 60 gtt/min

Calculate the hours to infuse. _____________

3. Order: 150 mL over 60 minutes


Calculate the number of drops per minute. _____________

4. Order: 1000 mL D5W/0.9% NS



Calculate the number of hours to infuse. _____________

5. Order: 500 mL over 4 hours


Calculate the number of drops per minute. _____________▲

▲▲

▲▲

MEDICATION PROBLEMS INVOLVING INTERMITTENT INFUSION

IV medications can be delivered over a specific amount of time by intermittent infu-sion. These medications require the use of an infusion pump. Some must be recon-stituted and further diluted in a specific type and amount of IV fluid and deliveredover a limited time. Others do not need to be reconstituted, but must be furtherdiluted in a specific type and amount of IV fluid and delivered over a limited time.


When adding reconstitutedmedications to an IV solu-tion, always check a nursingdrug reference for compati-bility of the solutions. Toprevent precipitation and/oravoid extravasations, cer-tain medications must bemixed in certain fluids andthen further diluted.

Example: Dilantin®(phenytoin) must bereconstituted with normalsaline (0.9% NaCl) andnever administered into anIV line of dextrose in water(D5W). Dilantin may onlybe further diluted withnormal saline (0.9%NaCl).

Example: Erythromycinmust be reconstituted withsterile water and may befurther diluted in normalsaline (0.9% NaCl) or dex-trose in water (D5W).

Example: Acyclovir mustbe reconstituted with ster-ile water and furtherdiluted in varyingstrengths and combina-tions of normal saline(0.9% NaCl) and dextrosein water (D5W).


Thin kingit

ThroughThis order contains twoproblems. The first involveshow many milliliters to drawfrom the vial after reconsti-tution, and the secondinvolves how many millilitersper hour to set the IV pump.



When adding reconstitutedsolutions to an IV bag, thegeneral rule is to includethe volume in the totalamount to be calculated forIV administration if thereconstituted solution is10% or more of the total IVsolution (Example: 10% of100 mL � 10 mL � 110 mLor 10% of 50 mL � 5 mL or55 mL).

E X A M P L E 5 . 1 2

The physician ordered erythromycin 500 mg IV every 6 hours for infection.The pharmacy sends a vial labeled: Erythromycin 1 g. The nursing drug ref-erence provides information to reconstitute 1 g of erythromycin with 20 mLof sterile water and further dilute in 250 mL of 0.9% NS and to infuse over1 hour.

How many milliliters will you draw from the vial after reconstitution?


Step 1

How many milliliters will you draw from the vial after reconstitution?

Given quantity = 500 mgWanted quantity = mLDose on hand = 1 g/20 mL

Random method:

The wanted quantity is 10 mL, and is the amount that will need to be drawn from

the vial and added to the 250 mL of 0.9% NS. After adding the 10 mL to the IV

bag, the IV bag will now contain 260 mL.

Step 2


Given quantity = 260 mL/1 hrWanted quantity = mL/hr

Sequential method:

The IV pump is set at 260 mL/hr to infuse the 500 mg of erythromycin ordered

by the physician.

260 mL

11 hr�

260

hr

260 mL

500 mg

1 g 1000 mg 1 1� 10 mL

20 mL 1 g 5 × 2 10




Step 2 (alternative): If an IV pump was unavailable, the infusion could bedelivered by gravity using IV tubing with a drop factor of 10 gtt/mL.

Calculate the drops per minute required to infuse the IV volume.

Given quantity = 260 mL/1 hrWanted quantity = gtt/minDrop factor = 10 gtt/mL

Sequential method:

Exercise 5.5 Medication Problems Involving

Intermittent Infusion


1. Order: ampicillin 250 mg IV every 4 hours for infection

Supply: ampicillin 1-g vial

Nursing drug reference: Reconstitute with 10 mL of 0.9% NS and further

dilute in 50 mL NS. Infuse over 15 min.



Calculate the drops per minute with a drop factor of 10 gtt/mL. _____________

2. Order: clindamycin 0.3 g IV every 6 hours for infection

Supply: clindamycin 600 mg/4-mL vial

Nursing drug reference: Dilute with 50 mL 0.9% NS and infuse over

15 min.




▲▲

▲▲

▲▲

260 × 1 × 1260 mL

mL1 hr 60 min 1 × 6�

10 gtt 1 hr 260 43.3 or 43 gtt

6 min



3. Order: Mezlin 3 g IV every 4 hours for infection

Supply: Mezlin 4-g vial

Nursing drug reference: Reconstitute each 1-g vial with 10 mL of 0.9% NS

and further dilute in 100 mL 0.9% NS to infuse over 1 hr.




4. Order: Unasyn 1000 mg IV every 6 hours for infection


Nursing drug reference: Reconstitute with 4 mL of 0.9% NS and further

dilute with 100 mL NS to infuse over 1 hr.




5. Order: Zantac 50 mg IV every 6 hours for ulcers

Supply: Zantac 25-mg/mL vial

Nursing drug reference: Dilute with 50 mL 0.9% NS to infuse over 30 min.




▲▲

▲▲

▲▲

▲▲

▲



Summary

This chapter has taught you to calculate two-factor medication problems involvingthe weight of the patient, reconstitution of medications, and the amount of timeover which medications and intravenous fluids can be safely administered. Todemonstrate your ability to calculate medication problems accurately, complete thefollowing practice problems.

Practice Problems for Chapter 5 Two-Factor Medication

Problems


1. Order: verapamil 0.2 mg/kg IV for arrhythmia

Supply: verapamil (Isoptin) 5 mg/2 mL

Child’s weight: 10 lb


2. Order: Tylenol Elixir 10 mg/kg every 4 hours prn for fever

Supply: Tylenol Elixir 160 mg/5 mL

Child’s weight: 8 kg


3. Order: Fortaz 1.25 g IV every 8 hours for infection

Supply: Fortaz 2-g vial

Nursing drug reference: Dilute each 2 g with 10 mL sterile water for injection.

❊ How many milliliters will you draw from the vial after reconstitution? _____________

4. Order: Unasyn 750 mg IV every 8 hours for infection


Nursing drug reference: Reconstitute with 4 mL of sterile water for injection.


5. Order: heparin 700 units/hr for anticoagulation

Supply: heparin 25,000 units/250 mL NS

❊ At how many milliliters per hour will you set the IV pump? _____________

6. Information obtained by the nurse: Zantac 150 mg in 250 mL NS is

infusing at 11 mL/hr.

❊ How many milligrams per hour is the patient receiving? _____________


7. Order: 1000 mL D5W/0.9% NS to infuse over 8 hours


❊ Calculate the number of drops per minute. _____________

8. Order: Infuse 750 mL NS



❊ Calculate the number of hours to infuse. _____________

9. Order: vancomycin 10 mg/kg IV every 8 hours for infection

Supply: vancomycin 500-mg vial

Infant’s weight: 20 lb

Nursing drug reference: Dilute each 500-mg vial with 10 mL of sterile water

for injection and further dilute in 100 mL of 0.9% NS to infuse

over 1 hr.


❊ Calculate the milliliters per hour to set the IV pump. _____________

❊ Calculate the drops per minute with a drop factor of 10 gtt/mL. _____________

10. Order: acyclovir 355 mg IV every 8 hours for herpes

Supply: acyclovir 500-mg vial

Nursing drug reference: Reconstitute each 500 mg with 10 mL of sterile water

for injection and further dilute in 100 mL NS to infuse over 1 hr.




11. Order: Diltiazem hydrochloride (Cardizem) 0.25 mg/kg IV push over

2 minutes for atrial fibrillation.

Supply: Cardizem vial labeled 5 mg/mL.

Nursing drug reference: May be administered by direct IV over 2 minutes

or as an infusion.

Patient’s weight: 80 kg.

❊ How many milliliters will you give via IV push over 2 minutes? _____________



12. Order: Pantoprazole sodium (Protonix) 40 mg IV every 12 hours to infuse

over 15 minutes for treatment of ulcerated GERD.

Supply: Protonix 40 mg powder.

Nursing drug reference: Reconstitute 40 mg powder with 10 mL 0.9% NS

and further dilute in 100 mL 0.9% NS or D5W to yield 0.4 mg/mL.

❊ Calculate the milliliters per hour to set the IV pump to adminis-ter the infusion over 15 minutes. _____________

13. Order: Diltiazem hydrochloride (Cardizem) 10 mg/hr continuous IV infu-

sion for atrial fibrillation.

Supply: Cardiazem 125 mg/25 mL syringe.

Nursing drug reference: May be administered by direct IV over 2 minutes or

as an infusion. For IV infusion, add Cardizem to 100 mL of 0.9% NS or D5W

(100 mL � 25 mL � 125 mL) to yield 1 mg/mL.


14. Order: Benazepril hydrochloride (Lotensin) 0.2 mg/kg PO as monotherapy

for hypertension.

Supply: Lotensin suspension 150 mL yields 2 mg/mL.

Child’s weight: 40 kg.


15. Order: Lithium carbonate (Lithium) 1.2 g/day in three divided doses PO for

manic-depressive disorder.

Supply: Lithium 300 mg/5 mL syrup.

❊ How many milliliters per dose will you give? _____________

16. Order: Levofloxacin (Levaquin) 250 mg IV over 90 minutes for gonococcal

infection.

Supply: Levaquin premixed 500 mg/100 mL D5W (yields 5 mg/mL).

❊ How many milliliters per hour will you set the IV pump? _____________

17. Order: Heparin 1200 units/hr continuous IV infusion.

Supply: Heparin 25,000 units/250 mL of D5W.

❊ How many milliliters per hour will you set the IV pump? _____________




18. The nurse checks the IV pump and documents that the pump is set at and

delivering 18 mL/hr of heparin. The IV bag hanging is labeled: Heparin

25,000 units/250 mL.

❊ How many units per hour is the patient receiving? _____________

19. Order: 1000 mL 0.9% NS/D5W to infuse over 8 hours.

Drop factor: 10 gtt/mL.


20. Order: 1000 mL D5W/0.9% NS.


Infusion rate: 15 gtt/min.



Chapter 5 Post-Test Two-Factor Medication

Problems

Name Date

1. Order: Furosemide 2 mg/kg PO every 8 hours for congestive heart failure



Courtesy of Roxane Laboratories.

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY




2. Order: meperidine 1.5 mg/kg PO every 4 hours for pain

The child weighs 22 lb.



3. Order: Epogen 100 units/kg IV tid for anemia secondary to chronic renal

failure

The patient weighs 160 lb.


Courtesy of Amgen, Inc.

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY



4. Order: Amoxicillin/clavulanate Potassium 10 mg/kg PO every 8 hours for

otitis media

Nursing drug reference: Dilute with 1 teaspoon (5 mL) of tap water

and shake vigorously to yield 125 mg per 5 mL.


❊ How many milliliters will you give after reconstitution? _____________

5. The physician orders heparin to infuse at 1300 units/hr continuous

IV infusion.

The pharmacy sends an IV bag labeled heparin 25,000 units in 250 mL.


6. A patient is receiving heparin 25,000 units in 250 mL infused at 25 mL/hr.

❊ How many units per hour is the patient receiving? _____________

AMOXICILLIN/CLAVULANATE

POTASSIUM

FOR ORAL SUSPENSION

STERILE CEFAZOLIN

equivalent to 1 gram cefazolinSODIUM (LYOPHILIZED)

1 × 5 mL (when reconstituted)

125 mg/5 mL

Patient Starter

Package

store dry powder at room temperature.After mixing, refrigerated, keep tightlyclosed and use within 24 hours.Shake well before using.Directions for mixing: Tap bottleuntil all powder flows freely. Addapproximately 1 teaspoonful(5 mL) of water; shake vigorously.When reconstituted, each 5 mLwill contain 125 mg amoxicillinas the trihydrate and 31.25 mgclavulanic acid as clavulanatepotassium.

Use

onl

y if

inne

r se

al is

inta

ct.

Cau

tio

n: F

eder

al la

w p

rohi

bits

disp

ensi

ng w

ithou

t pre

scrip

tion.

LOT

EX

P.

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12





7. The physician orders morphine sulfate 2 mg/hr continuous IV for

intractable pain related to end-stage lung cancer.

The pharmacy sends an IV bag labeled morphine sulfate 100 mg in 250 mL.


8. Order: 1000 mL D5W/1/2 NS with 20 mEq of KCl to infuse in 12 hours



9. Order: Azactam 500 mg IV every 12 hours for septicemia

Supply: Azactam 1-g vials

Nursing drug reference: Dilute each 1-g vial with 10 mL of sterile water for injec-

tion and further dilute in 100 mL of NS to infuse over 60 minutes.




1 2 3 4 5 6 7 8 9

10m

L



10. Order: Cefazolin 6.25 mg/kg IV every 6 hours for pneumonia

The child weighs 38.2 kg.

Nursing drug reference: Dilute each 1-g vial with 10 mL of sterile water for

injection and further dilute 50 mL of NS to infuse over 30 minutes.




STERILE CEFAZOLIN

SODIUM

(LYOPHILIZED)

equivalent to

1 gram cefazolin

Before reconstitution protectfrom light and store between15° and 30° C (59° and 86°F).Usual Adult Dosage: 250 mgto 1 gram every 6 to 8 hours.See accompanyingprescribing information.Reconstituted Ancef is stable24 hours at room temperatureor 10 days if refrigerated(5°C or 41°F)

LOT

EX

P.



5

Random method:

Exercise 5.2 Medication Problems

Involving Reconstitution

1

Random method:

2

Sequential method:

3

Random method:

Random method using yield:

4

Random method:

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mL fl oz=15 mL

10 mL

5 mL

12

�2.04 or2 mL

1 mg mL 1 kg 45 lb 1 × 1 × 45 45

kg 10 mg 2.2 lb 10 × 2.2 22

0.01 mg mL 1 kg 20 lb 0.01 × 1 × 20 0.2

kg 0.1 mg 2.2 lb 0.1 × 2.2 0.22� 0.9 mL

0.5 mg mL

kg 25 mg

1 kg

2.2 lb 25 × 2.2 55

45 lb 0.5 × 1 × 45 22.5� 0.4 mL

50 mcg

kg

mL

8 mg

1 mg

1000 mcg

1 kg

2.2 lb 8 × 100 × 2.2

75 lb 5 × 1 × 1 × 75

1760

375� mL

375

1760� 0.2 mL

10 mg

kg

1 kg 70 lb 5 mL

2.2 lb 300 mg

10 × 1 × 7 × 5

2.2 × 30

350

66� 5.3 or 5 mL

50 mg 4 mL 1 g 40 kg 5 × 4 × 1 × 4 80

kg 1.5 g 1000 mg 1.5 × 10 15

500 mg 50 mL

1 g

1 g

1000 mg

5 × 5

1

25

1� 25 mL

250 mg 10 mL

500 mg

25 × 1

5

25

5� 5 mL

�5.33 or

5 mL

50 mg 1 mL 40 kg 50 × 1 × 40 2000

kg 375 mg 375 375�

5.33 or

5 mL

750 mg 20 mL 1 g 75 × 2 × 1 150

1 g 1000 mg 1 × 10 10� 15 mL

ANSWER KEY FOR CHAPTER 5: TWO-FACTOR MEDICATION PROBLEMS

Exercise 5.1 Pediatric Medication

Problems Involving Weight

1

Sequential method:

2

Sequential method:

3

Sequential method:

4

Random method:

3 mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 mL


5

Sequential method:


Involving Intravenous

Pumps

1

Sequential method:

2

Random method:

3

Sequential method:

4

Sequential method:

5

Sequential method:


Involving Drop Factors

1

Sequential method:

2

Sequential method:


3

Sequential method:

4

Sequential method:

5

Sequential method:


Involving Intermittent

Infusion

1

Random method:

Calculate milliliters per hour to set the IV pump.Sequential method:

Calculate drops per minute with a drop factor of 10 gtt/mL.Sequential method:

2

Random method:

Calculate milliliter per hour to set the IV pump.Sequential method:

1800 units 250 mL 18

hr 25,000 units�

18 mL

hr

35 mg 250 mL 1 g 35 × 25 875

hr 1 g 1000 mg 100 100�

8.75 or 9 mL

hr

30 mL 25,000 units 30 × 2500 75,000

hr 250 mL 25 25�

3000 units

hr

15 mL 1 g 1000 mg 15 × 100 1500

hr 250 mL 1 g 25 25�

60 mg

hr

900 units 500 mL 90 × 5 450

hr 25,000 units 25 25�

18 mL

hr

800 mL 15 gtt 1 hr 80 × 15 × 1 1200

8 hr mL 60 min 8 × 6 48�

25 gtt

min

250 mL 15 gtt min 1 hr 250 × 15 × 1 3750

mL 60 gtt 60 min 60 × 60 3600�

1.04 or

1 hr

30 mg 5 mL 1 kg 65 lb 3 × 5 × 1 × 65 975

kg 500 mg 2.2 lb 50 × 2.2 110�

8.86 or

8.9 mL150 mL 10 gtt 150 × 1 150

60 min mL 6 6�

25 gttmin

1000 mL 15 gtt min 1 hr 10 × 15 × 1 150

mL 50 gtt 60 min 5 × 6 30� 5 hr

500 mL 15 gtt 1 hr 50 × 15 × 1 750

4 hr mL 60 min 4 × 6 24�

31.25 or 31 gtt

min

250 mg 10 mL 1 g 25 × 1 25

1 g 1000 mg 10 10� 2.5 mL

50 mL 60 min 50 × 60 3000

15 min 1 hr 15 × 1 15�

200 mL

hr

50 mL 10 gtt 50 × 10 500

15 min mL 15 15�

33.33 or 33 gtt

min

0.3 g 4 mL 1000 mg 0.3 × 4 × 10 12

600 mg 1 g 6 × 1 6� 2 mL

50 mL 60 min 50 × 60 3000

15 min 1 hr 15 × 1 15�

200 mL

hr



3

Sequential method:



4

Random method:



5

Sequential method:


Calculate milliliters per hour to set the IV pump.Random method:


Practice Problems

1

Sequential method:

2

Sequential method:

3

Sequential method:

4

Random method:

5

Sequential method:

6

Sequential method:

50 mL 15 gtt 50

15 min mL �

50 gtt

min

3 g 40 mL 3 × 40 120� 30 mL

4 g 4 4

130 mL 130

1 hr 1�

130 mL

hr

130 mL 20 gtt 1 hr 130 × 2 260 �

1 hr mL 60 min 6 6

43.33 or 43 gtt

min

1000 mg 4 mL 1 g 4 × 1 4

1.5 g 1000 mg 1.5 1.5�

2.66 or 2.7 mL

100 mL 100

1 hr 1�

100 mL

hr

100 mL 20 gtt 1 hr 100 × 2 200 �

1 hr mL 60 min 6 6

33.33 or 33 gtt

min

50 mL 60 min 50 × 6 300

30 min 1 hr 3 × 1 3�

100 mL

hr

50 mL 10 gtt 50 × 1 50

30 min mL 3 3�

16.66 or 17 gtt

min

0.2 mg 2 mL 1 kg 10 lb 0.2 × 2 × 1 × 10 4 �

kg 5 mg 2.2 lb 5 × 2.2 11

0.36 or

0.4 mL

10 mg 5 mL 8 kg 1 × 5 × 8 40� 2.5 mL

kg 160 mg 16 16

1.25 g 10 mL 1.25 × 10 12.5 � 6.25 or 6.3 mL

2 g 2 2

750 mg 4 mL 1 g 75 × 4 × 1 300� 2 mL

1.5 g 1000 mg 1.5 × 100 150

700 units 250 mL 7�

hr 25,000 units

7 mLhr50 mg mL 50

� 2 mL

25 mg 25

11 mL 150 mg 11 × 15 165�

hr 250 mL 25 25

6.6 mg

hr


13

OR

14

15

16

OR

17

18

19

20

7

Sequential method:

8

Sequential method:

9

Sequential method:

Sequential method:

Sequential method:

10

Sequential method:

Calculate mL per hour to set the IV pump.

Calculate drops per minute with a drop factor of 20 gtt/mL.

Sequential method:

11

12


750 mL 15 gtt min 1 hr 75 × 15 × 1 1125 �

mL 18 gtt 60 min 18 × 6 108

10.41 or

10 hr

10 mg 10 mL 1 kg 20 lb 1 × 1 × 1 × 20 20 � 1.8 mL

kg 500 mg 2.2 lb 5 × 2.2 11

1000 mL 20 gtt 1 hr 1000 × 2 × 1 2000�

8 hr mL 60 min 8 × 6 48

41.66 or 42 gtt

min

100 mL 100

1 hr 1 hr

100 mL�

�101.8 mL 10 gtt 1 hr

1 hr mL 60 min

101.8 × 1 101.8 16.96 or 17 gtt

66 min

355 mg 10 mL

500 mg

355 × 1 355

50 50� 7.1 or 7 mL

100 mL

1 hr

100

1

100 mL

hr�

100 mL

1 hr

20 gtt

mL

1 hr

60 min

100 × 2

6

200 33.33 or 33 gtt

6 min�

1.2 g day 5 mL 1000 mg 1.2 × 5 × 10 60�

day 3 doses 300 mg 1 g 3 × 3 × 1 9

1200 units 250 mL 12�

12 mL

hr 25,000 units hr

6.66 or

7 mL dose

250 mg 100 mL 60 min 250 × 1 × 6 1500�

33.3 or 33 mL

90 min 500 mg 1 hr 9 × 5 × 1 45 hr

10 mg 125 mL 10�

10 mL

hr 125 mg hr

10 mg 1 mL 10�

10 mL

hr 1 mg hr

0.2 mg mL 40 kg 0.2 × 40 8� 4 mL

kg 2 mg 2 2

18 mL 25,000 units 18 × 2500 45,000�

1800 units

hr 250 mL 25 25 hr

250 mg mL 60 min 250 × 6 1500�

33.3 or 33 mL

90 min 5 mg 1 hr 9 × 5 × 1 45 hr

0.25 mg ml 80 kg 0.25 × 80 20�

kg 5 mg 5 5

4 mL IV pushover 2 minutes

1000 mL 10 gtt 1 hr 1000 × 1 × 1 1000�

20.83 or 21 gtt

8 hr mL 60 min 8 × 6 48 min

1000 mL 10 gtt min 1 hr 1000 × 1 × 1 1000� 11.11 or 11 hr

mL 15 gtt 60 min 15 × 6 90

40 mg mL 60 min 40 × 60 2400�

400 mL

15 min 0.4 mg 1 hr 15 × 0.4 × 1 6 hr


C H A P T E R 6Three-Factor Medication Problems

Objectives


1. Calculate three-factor–given quantity to one-factor–, two-factor–, or three-factor–wantedquantity medication problems involving aspecific amount of medication or intravenous(IV) fluid based on the weight of the patientand the time required for safe administration.

2. Calculate problems requiring reconstitutionor preparation of medications usinginformation from a nursing drug reference,label, or package insert.

When medications are ordered for infants and chil-dren, the dosage of medication (g, mg, mcg, gr)

based on the weight of the child must be considered aswell as how much medication the child can receive perdose or day.

Although the physician or nurse practitioner ordersthe medications, the nurse must be aware of the safe dosage range for administrationof medications. It is the responsibility of the nurse to check a nursing drug referencefor the right dosage before administering a medication to a child to prevent medica-tion errors.

When physicians or nurse practitioners order medications for critically ill patients,the patients must be closely monitored by the nurse for effectiveness of the medica-tions. Often, the medications or intravenous (IV) fluids must be titrated for effective-ness, with an increase or decrease in the dosage based on the patient’s response.

Factors involved in the safe administration of medications or IV fluids for the criti-cally ill patient include the dosage of medication based on the weight of the patientand the time required for administration. The medication may need reconstitution orpreparation by the nurse for immediate administration in a critical situation. Theweight of the patient also may need to be obtained daily to ensure accurate correlation

Outline

Exercise 6.1: Medication Problems Involving Dosage,

Weight, and Time 158

Practice Problems for Chapter 6: Three-Factor Medication Problems 164

Post-Test for Chapter 6: Three-Factor Medication Problems 169

Answer Key for Chapter 6: Three-Factor Medication Problems 175

1 5 1


LWBK732_c06_p151-178:LWBK732_c06_p151-178.qxd 11/22/10 9:27 AM Page 151

with the dosage of medication ordered. A nursing drug reference provides thenurse with information related to dosage, weight, and time for safe adminis-tration of medication.

To be able to calculate three-factor–given quantity to one-factor–, two-factor–, or three-factor–wanted quantity medication problems, it is necessaryto understand all of the components of the medication order and to be able tocalculate medication problems in a critical situation. This chapter will teachyou to calculate medication problems involving the dosage of medicationbased on the weight of the patient and the time required for safe administra-tion using dimensional analysis.


Three-factor–given quantity medication problems can be solved implementing thesequential method or the random method of dimensional analysis. The given quan-tity or the physician’s order now contains three parts, including a numerator (thedosage of medication ordered) and two denominators (the weight of the patientand the time required for safe administration).

Below is an example of this problem-solving method showing placement ofbasic dimensional analysis terms applied to a three-factor medication problem.

Unit Path


30 mg 5 mL 22 kg 30 × 5 × 22 3300 �

11 mL

kg/day 300 mg 300 300 day

E X A M P L E 6 . 1

The physician orders Tagamet for gastrointestinal ulcers 30 mg/kg/dayPO in four divided doses for a child weighing 22 kg. The dose on handis Tagamet 300 mg/5 mL.

How many milliliters per day will the child receive?

Given quantity � 30 mg/kg/dayWanted quantity � mL/dayDose on hand � 300 mg/5 mLWeight � 22 kg

Thin kingit

ThroughThe three-factor–givenquantity has been set upwith a numerator (30 mg)and two denominators(kg/day) leading across theunit path to a two-factor–wanted quantity, with anumerator (mL) and a deno minator (day). The con-version factors can now befactored into the unit pathto allow cancellation ofunwanted units.


CHAPTER 6 Three-Factor Medicat ion Problems 1 5 3

Step 1 Identify the three-factor–given quantity (the physician’s order),which contains three parts: a numerator (30 mg) and twodenominators (kg/day). Establish the unit path from the givenquantity (30 mg/kg/day) to the two-factor–wanted quantity(mL/day) using the sequential method of dimensional analysis and the necessary conversion factors.

Sequential method:

Step 2

Step 3

Step 4

30 mg �

mL

kg/day day

Unit Path


30 mg 5 mL �

mL

kg/ day 300 mg day

Unit Path


30 mg 5 mL 22 kg �

mL

kg/ day 300 mg day


Unit Path


30 mg 5 mL 22 kg 3 × 5 × 22 330 �

11 mL

kg/ day 300 mg 30 30 day

The dose on hand (300 mg/5 mL) has beenfactored in and placed sothat the wanted unit (mL)correlates with the wantedquantity (mL) and theunwanted unit (mg) is canceled.

The child’s weight (22 kg)has been factored in andset up to allow theunwanted unit (kg) to becanceled.

All the unwanted unitshave been canceled, andthe wanted units are placedto correlate with the two- factor–wanted quantity(mL/day). Multiply numera-tors, multiply denominators,and divide the product ofthe numer ators by the prod-uct of the denominators toprovide the numericalanswer. The wanted quan-tity is 11 mL/day.

The child is to receive 11 mL/day in four divideddoses; therefore, the con-version factor involves howmany doses are in a day (4 divided doses � day).



Step 5 Using dimensional analysis, calculate how many milliliters per dosethe child should receive.

Given quantity � 11 mL/dayWanted quantity � mL/dose

Step 6

The wanted quantity is 2.8 mL/dose, and the child will receive this orally (PO)

four times a day (qid).

The problem could have been set up to find the wanted quantity ofmilliliters per dose.

Step 6 (alternative).

Given quantity � 30 mg/kg/dayWanted quantity � mL/doseDose on hand � 300 mg/5 mLWeight � 22 kg

Sequential method:

The wanted quantity is 2.8 mL/dose, and the child will receive this orally (PO)

four times a day (qid).

11 mL �

mL

day dose

11 mL day 11� 2.75 or

2.8 mL

day 4 doses 4 dose

30 mg 5 mL 22 kg day 3 × 5 × 22 330 � 2.75 or

2.8 mL

kg/day 300 mg 4 doses 30 × 4 120 dose

E X A M P L E 6 . 2

As a prudent nurse, you are concerned that the child may be receivingan unsafe dosage of Tagamet; therefore, you want to identify how manymilli grams per kilogram per day (mg/kg/day) the child weighing 22 kg is re ceiving. The dosage of medication being given four times a day is 2.8 mL/dose. The dosage on hand is 300 mg/5 mL.

How many milligrams per kilogram per day is the child receiving?

Given quantity � 2.8 mL/doseWanted quantity � mg/kg/doseDose on hand � 300 mg/5 mLChild’s weight � 22 kg


Every new medicationorder for a child should becarefully reviewed forerrors related to dosage,route, and frequency.Many medication errorscan be eliminated if a double-check system is in place for all new medication orders.

Thin kingit

ThroughThe two-factor–given quan-tity (2.8 mL/dose) has beenfactored in with a numerator(2.8 mL) and a denominator(dose). The three-factor–wanted quantity(mg/kg/day) also has beenfactored in with a numerator(mg) and two denominators(kg/day).

The conversion factorshave been added, and allunwanted units have beencanceled from the problem.



Sequential method:

Step 1

Step 2

Step 3

The three-factor–wanted quantity is 30.5 mg/kg/day. The nursing drug refer-

ence identifies that 20 to 40 mg/kg/day in four divided doses is a safe dosage

of Tagamet for children. Therefore, the nurse is assured that the child is receiv-

ing a correct dosage. Dimensional analysis assists you to critically think

through any type of medication problem.

2.8 mL �

mg

dose kg/day

2.8 mL 300 mg 4 doses �

mg

dose 5 mL day 22 kg kg/day

2.8 mL 300 mg 4 doses 2.8 × 300 × 4 3360 �

30.54 or 30.5 mg

dose 5 mL day 22 kg 5 × 22 110 kg/day

E X A M P L E 6 . 3

The physician orders dobutamine 5 mcg/kg/min IV for cardiac failure.The pharmacy sends an IV bag labeled: dobutamine 250 mg/50 mLD5W/0.45% NS. The patient weighs 165 lb.

Calculate the milliliters per hour at which to set the IV pump.

Given quantity � 5 mcg/kg/minWanted quantity � mL/hrDose on hand � 250 mg/50 mLWeight � 165 lb

Step 1 Identify the three-factor–given quantity (the physician’s order) containing three parts, including the numerator (5 mg) and twodenominators (kg/min). Establish the unit path from the three- factor–given quantity to the two-factor–wanted quantity (mL/hr).

Random method:

5 mcg �

mL

kg/min hr


The wanted unit (mg) isplaced in the numerator tocorrelate with the wantedquantity (mg) also in the nu -me rator. The wanted units (kg and day) are in thedenom inator to correlatewith the wanted quantity(kg and day) in the denomi-nator.


Knowing the Six Rights ofmedication administrationcan help to eliminate med-ication errors but anotherimportant consideration isbeing aware of the safedosage range for each med-ication being administered.

A Nursing Drug Refer-ence lists the safe dosagerange for adults, children,and infants. It is theresponsibility of the nurseto be familiar with safedosage ranges to preventmedication errors.

Thin kingit

ThroughThe three-factor–givenquantity has been set upwith a numerator (5 mg) andtwo denominators (kg/min)leading across the unit pathto a two-factor–wantedquantity with a numerator(mL) and a denominator (hr).By using the randommethod of dimensionalanalysis, the conversion fac-tors are factored to cancelout unwanted units.

(Thinking it Through continues on

page 156)



Step 2

Step 3

Step 4

Step 5

Step 6

The 4.5 mL/hr is the wanted quantity and is the answer to the problem. Intra-

venous pumps used in critical care can be set to deliver amounts including

decimal points so it is not necessary to round up the answer.

5 mcg 60 min �

mL

kg/min 1 hr hr

5 mcg 60 min 50 mL �

mL

kg/min 1 hr 250 mg hr

5 mcg 60 min 50 mL 1 mg �

mL

kg/min 1 hr 250 mg 1000 mcg hr

5 mcg 60 min 50 mL 1 mg 1 kg 165 lb�

mL

kg/min 1 hr 250 mg 1000 mcg 2.2 lb hr

5 mcg 60 min 50 mL 1 mg 1 kg 165 lb�

mL

kg/min 1 hr 250 mg 1000 mcg 2.2 lb hr

5 × 6 × 5 × 1 × 165 24,750�

4.5 mL

25 × 100 × 2.2 5500 hr

E X A M P L E 6 . 4

The nurse has been monitoring the hemodynamic readings of a patientweighing 165 lb receiving dobutamine, 250 mg in 50 mL of D5W/0.45%NS, and has received additional orders from the physician to titrate for effectiveness.

The IV pump is now set at 9 mL/hr, and the physician wants toknow how many micrograms per kilogram per minute thepatient is now receiving.

The unwanted unit (min)has been canceled by factor-ing the conversion factor(1 hr � 60 min), and thewanted unit correspondswith the wanted quantitydenominator (hr).

The dose on hand(250 mg/50 mL) has beenfactored in and placed sothat the wanted unit (mL)corresponds with thewanted quantity numerator(mL).

The conversion factor(1 mg � 1000 mcg) hasbeen factored in to cancelthe unwanted units (mg andmcg).

The final conversion fac-tors (1 kg � 2.2 lb) and theweight of the patient havebeen factored in to cancelthe remaining unwantedunits (kg and lb). All theunwanted units have beencanceled, and the wantedunits (mL and hr) remain inposition to correlate withthe two-factor–wantedquantity (mL/hr). Multiplythe numerators, multiply thedenominators, and dividethe product of the numera-tors by the product of thedenominators to providethe numerical value for thetwo-factor– wanted quantity.

Thin kingit

ThroughThe two-factor–given quan-tity is identified as the infor-mation that the nurseobtained from the IV pump,and the three-factor–wanted quantity is the infor-mation that the physicianhas requested.



Given quantity � 9 mL/hrWanted quantity � mcg/kg/minDose on hand � 250 mg/50 mLWeight � 165 lb

Step 1

Step 2

Sequential method:

Step 3

Step 4

Step 5

Step 6

The nurse can inform the physician that the patient is now receiving

10 mcg/kg/min infusing at 9 mL/hr.

9 mL �

mcg

hr kg/min

9 mL 250 mg �

mcg

hr 50 mL kg/min

9 mL 250 mg 1000 mcg �

mcg

hr 50 mL 1 mg kg/min

9 mL 250 mg 1000 mcg 1 hr �

mcg

hr 50 mL 1 mg 60 min kg/min

9 mL 250 mg 1000 mcg 1 hr 2.2 lb �

mcg

hr 50 mL 1 mg 60 min 1 kg 165 lb kg/min

9 mL 250 mg 1000 mcg 1 hr 2.2 lb �

mcg

hr 50 mL 1 mg 60 min 1 kg 165 lb kg/min

9 × 25 × 100 × 2.2 49,500�

10 mcg

5 × 6 × 1 × 165 4950 kg/min

The dose on hand (the IVfluid that is presently infusing)has been factored in to can-cel the unwanted unit (mL).

The conversion factor(1 mg = 1000 mcg) hasbeen factored in to cancelthe unwanted unit (mg). Thewanted unit (mcg) remainsand corresponds with thewanted quantity in the numerator.

The conversion factor(1 hr = 60 min) has been factored in to cancel theunwanted unit (hr). Thewanted unit (min) remainsplaced in the denominator.

The conversion factor(1 kg = 2.2 lb) has been factored in to correspondwith the wanted quantitydenominator (kg). Theweight of the patient also isfactored in to cancel theunwanted unit (lb). After allunwanted units have beencanceled and the wantedunits have been identified,multiply the numerators,multiply the denominators,and divide the product ofthe numerators by the prod-uct of the denominators toprovide the numerical valuefor the wanted quantity.


When caring for criticallyill patients, the nurse isresponsible for titratingmedication for the desiredeffectiveness (decrease inchest pain, increase in urineoutput, or increase in blood pressure).

(Preventing Medication Errors

continues on page 158)



The weight of a patient isextremely important whenadministering medicationsto a critically ill patientbecause a change in weight(either increased ordecreased) can change theeffectiveness of the med-ication. To prevent med-ication errors, a dailyweight is obtained onevery critically ill patient.

Dimensional analysis is a problem-solving method that uses critical thinking.When implementing the sequential method or the random method of dimensionalanalysis, the medication problem can be set up in a number of different ways, witha focus on the correct placement of conversion factors to allow unwanted units to becanceled from the unit path.

Dimensional analysis is a problem-solving method that nurses can use to calculate a variety of medication problems in the hospital, outpatient, or home careenvironment. The medication problems may involve one-factor–, two-factor–, orthree-factor–given quantity medication orders, resulting in one-factor–, two-factor–,or three-factor–wanted quantity answers.

With advanced nursing and home care nursing resulting in increased autonomy,it is more important than ever that nurses be able to accurately calculate medicationproblems. Dimensional analysis provides the opportunity to use one problem-solving method for any type of medication problem, thereby increasing consistencyand decreasing confusion when calculating medication problems.

Exercise 6.1 Medication Problems Involving Dosage,

Weight, and Time


1. Order: Furosemide 2 mg/kg/day PO in two divided doses for congestive

heart failure

Supply: Furosemide 40 mg/5 mL


How many milliliters per dose will you give? _____________▲

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY




2. Order: Cefazolin 40 mg/kg/day in divided doses every 8 hours for infection

Supply: Cefazolin 1 g


Nursing drug reference: Reconstitute with 10 mL of sterile water for

injection.

How many milliliters per dose will you draw from the vialafter reconstitution? _____________

▲

3. Order: Dilantin 6 mg/kg/day in divided doses every 12 hours for seizures

Supply: Dilantin 125 mg/5 mL


How many milliliters per dose will you give? _____________

▲

STERILE CEFAZOLIN

SODIUM

(LYOPHILIZED)

equivalent to

1 gram cefazolin

Before reconstitution protectfrom light and store between15° and 30°C (59° and 86°F).Usual Adult Dosage: 250 mgto 1 gram every 6 to 8hours. Seeaccompanyingprescribinginformation.ReconstitutedAncef isstable 24 hours atroom temperatureor 10 days ifrefrigerated(5°C or 41°F).

N

LOT

EX

P.3

1




4. Order: prednisolone 1.5 mg/kg/day in four divided doses for inflammation

Supply: prednisolone 6.7 mg/5 mL



▲

5. Order: Cleocin 10 mg/kg/day IV in divided doses every 8 hours for

infection

Supply: Cleocin 300 mg/2 mL



▲

Courtesy of Fisons Pharmaceuticals.

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

Courtesy of Upjohn Company.



6. Order: dopamine 5 mcg/kg/min IV to increase blood pressure

Supply: dopamine 400-mg vial

Supply: 250 cc D5W

Patient’s weight: 200 lb

How many milliliters will you draw from the vial to equal 400 mg? _____________


▲▲





7. Information obtained by the nurse: Nipride 50 mg/250 mL D5W is



How many micrograms per kilogram per minute is thepatient receiving? _____________

8. Order: Inocor 5 mcg/kg/min IV for congestive heart failure

Supply: Inocor 100 mg/100 mL of 0.9% NS



▲▲




9. Information obtained by the nurse: Nipride 50 mg/250 mL D5W is

infus ing at 46 mL/hr.


How many micrograms per kilogram per minute is the patient receiving? _____________

10. Order: bretylium 5 mg/kg in 50 mL D5W IV over 30 minutes for arrhythmia

Supply: bretylium 500-mg vial


How many milliliters will you draw from the vial to equal 500 mg? _____________


▲▲

▲





Summary

This chapter has taught you to calculate three-factor medication problems involving thedosage of medication, the weight of the patient, and the amount of time over whichmedications or IV fluids can be safely administered. Using the sequential method or therandom method of dimensional analysis, demonstrate your ability to calculate medica-tion problems accurately by completing the following practice problems.

Practice Problems for Chapter 6 Three-Factor Medication

Problems


1. Order: amrinone 8 mcg/kg/min IV for congestive heart failure

Supply: amrinone 100 mg/100 mL of 0.9% NS



2. Order: Tagamet 40 mg/kg/day PO in four divided doses for gastrointestinal ulcers

Supply: Tagamet 300 mg/5 mL



3. Information obtained by the nurse: dopamine 200 mg in 500 mL D5W is

infusing at 45 mL/hr for a patient weighing 60 kg.

❊ How many micrograms per kilogram per minute is the patient receiving? _____________

4. Order: dopamine 2 mcg/kg/min IV for decreased cardiac output

Supply: dopamine 400 mg/500 mL



5. Order: Neupogen 5 mcg/kg/day SQ for 2 weeks for neutropenia

Supply: Neupogen 300 mcg/mL


❊ How many micrograms per day will you give? _____________


6. Order: aminophylline 0.5 mg/kg/hr IV loading dose for bronchodilation

Supply: aminophylline 250 mg/250 mL D5W



7. Order: furosemide 2 mg/kg/day PO for congestive heart failure

Supply: furosemide 10 mg/mL


❊ How many milliliters per day will you give? _____________

8. Information obtained by the nurse: Nipride 200 mg in 1000 mL D5W is

infusing at 15 mL/hr for a patient weighing 100 kg.

❊ How many micrograms per kilogram per minute is the patientreceiving? _____________

9. Information obtained by the nurse: A child weighing 65 lb is receiving

10 mL of Tagamet PO qid from a stock bottle labeled: Tagamet

300 mg/5 mL.

❊ How many milligrams per kilogram per day is the child receiving? _____________

10. Information obtained by the nurse: aminophylline 250 mg/250 mL 0.9%

NS is infusing at 25 mL/hr for a patient weighing 50 kg.

❊ How many milligrams per kilogram per hour is the patient receiving? _____________

11. Order: Gabapentin (Neurontin) 10 mg/kg/day PO in three divided doses

for seizures.

Supply: Neurontin 250 mg/5 mL solution.

Child’s weight: 60 lb.

❊ How many milliliters per dose will the child receive? _______

12. Information obtained by the nurse: A 10-year-old child weighing 60 lb is

receiving 2 mL/dose PO three times a day of gabapentin (Neurontin) for

seizures from a stock bottle labeled 250 mg/5 mL.

Nursing drug reference: Children ages 3–12 years should be receiving

10–15 mg/kg/day in three divided doses.

❊ How many mg/kg/day is the child receiving? _____________





13. Order: Tobramycin sulfate 3 mg/kg/day IV in three doses every 8 hours for

infection.

Patient’s weight: 60 kg

Supply: Tobramycin 60 mg in 100 mL D5W

Nursing drug reference: Mix 60 mg/mL in 100 mL D5W and infuse over

60 minutes.

❊ How many milligrams per dose should the patient receive? _____________


14. Order: Amiodarone hydrochloride (Cordarone) 7 mcg/kg/min IV for

unstable ventricular tachycardia.

Supply: Amiodarone 500 mg/250 mL 0.9% NS


❊ Calculate the milliliters per hour to set the IV pump. _________

15. Information obtained by the nurse: A patient who weighs 80 kg is receiving

15 mL/hr of Amiodarone hydrochloride (Cordarone) for unstable ventricu-

lar tachycardia from an IV bag labeled 500 mg/250 mL 0.9% NS.

❊ How many mcg/kg/min is the patient receiving? _____________

16. Order: Pentamidine isethionate (Pentam 300) 4 mg/kg/day IV for 14 days

for pneumonia secondary to Pneumocystis carinii.

Supply: Pentamidine 300 mg/250 mL D5W

Nursing drug reference: Infuse slowly over 60 minutes.



17. Order: Dopamine hydrochloride (Dopamine) 20 mcg/kg/min IV for cardio-

genic shock.

Supply: Dopamine 400 mg/250 mL 0.9% NS





18. Information obtained by the nurse: Dopamine hydrochloride (Dopamine)

400 mg in 250 mL 0.9% NS is infusing at 30 mL/hr.



19. Order: Nitroprusside sodium (Nitropress) 5 mcg/kg/min IV for hyperten-

sive crisis.

Supply: Nitropress 50 mg/250 mL D5W



20. Information obtained by the nurse: Nitroprusside sodium (Nitropress)

50 mg in 250 mL D5W is infusing at 80 mL/hr.





Chapter 6 Post-Test Three-Factor Medication

Problems

Name Date

1. Order: morphine sulfate 0.3 mg/kg/dose PO every 4 hours for pain

Supply: morphine sulfate 10 mg/5 mL




1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY






2. Order: filgrastim 5 mcg/kg/day for myelosuppression secondary to

chemotherapy administration

Supply: filgrastim 480 mcg/1.6 mL



3. Order: Epogen 100 units/kg/day SQ three times weekly for anemia

secondary to AZT administration

Supply: Epogen 10,000 units/mL





4. Order: digoxin 25 mcg/kg/day PO every 8 hours for congestive heart failure

Supply: digoxin 0.25 mg/5 mL


❊ How many milliliters will you give per day? _____________

❊ How many milliliters will you give per dose? _____________1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY




5. Order: clindamycin 10 mg/kg/day IV in three divided doses for respiratory

tract infection

Supply: clindamycin 150 mg/mL


❊ How many milliliters per dose will you draw from the vial? _____________



6. Order: Claforan 100 mg/kg/day IV in two divided doses for infection

Supply: Claforan 1 g/10 mL

Neonate’s weight: 2045 g


7. Order: gentamicin 2.5 mg/kg/dose IV every 12 hours for gram-negative

bacillary infection

Supply: gentamicin 40 mg/mL


❊ How many milligrams per dose will the neonate receive? _____________


8. Order: ampicillin 100 mg/kg/day IV in divided doses every 12 hours for

respiratory tract infection

Supply: ampicillin 125 mg/5 mL


❊ How many milligrams per dose will the neonate receive? _____________


9. Order: Solu-Medrol 5.4 mg/kg/hr IV for acute spinal cord injury

Supply: Solu-Medrol 125 mg/2 mL


❊ How many milligrams per hour will the patient receive? _____________

10. Order: aminophylline 0.8 mg/kg/hr IV for respiratory distress

Supply: aminophylline 250 mg/100 mL







Involving Dosage,

Weight, and Time

1

Sequential method:

2

Random method:

3

Sequential method:

4

Sequential method:

5

Sequential method:

6

Sequential method:

Random method:

2 mg 5 mL 20 kg day 2 × 5 × 2 20 �

2.5 mL

kg/day 40 mg 2 doses 4 × 2 8 dose

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

40 mg 10 mL day 1 kg 30 lb 1 g �

mL

kg/day 1 g 3 doses 2.2 lb 1000 mg dose

4 × 1 × 3 12 �

1.81 or 1.8 mL

3 × 2.2 6.6 dose

3 mL

6 mg 5 mL 1 kg 45 lb day �

mL

kg/day 125 mg 2.2 lb 2 doses dose

6 × 5 × 1 × 45 1350 �

2.45 or 2.5 mL

125 × 2.2 × 2 550 dose

150 �

5.59 or 5.6 mL

26.8 dose

1.5 mg 5 mL 20 kg day 1.5 × 5 × 20�

mL

kg/day 6.7 mg 4 doses 6.7 × 4 dose

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

10 mg 2 mL 1 kg 1 day 50 lb 1 × 2 × 1 × 1 × 5 10 �

0.5 mL

kg/day 300 mg 2.2 lb 3 doses 3 × 2.2 × 3 19.8 dose

3 mL

400 mg mL 40 � 10 mL

40 mg 4

5 × 6 × 2 × 26 × 1 1560 �

17.7 or 18 mL

2.2 × 4 × 10 88 hr

5 mcg 60 min 1 kg 200 lb 260 mL 1 mg �

mL

kg/min 1 hr 2.2 lb 400 mg 1000 mcg hr

ANSWER KEY FOR CHAPTER 6: THREE-FACTOR MEDICATION PROBLEMS



7

Sequential method:

8

Random method:

9

Sequential method:

10

Sequential method:

Sequential method:

Practice Problems

1

Random method:

2

Sequential method:

3

Sequential method:

4

Random method:

5

Random method:

22 × 5 × 10 × 2.2 2420 �

1.008 or 1 mcg

25 × 6 × 1 × 16 2400 kg/min

22 mL 50 mg 1 hr 1000 mcg 2.2 lb �

mcg

hr 250 mL 60 min 1 mg 1 kg 160 lb kg/min

5 × 1 × 18 × 6 540 �

24.5 or 25 mL

10 × 2.2 22 hr

5 mcg 100 mL 1 mg 1 kg 180 lb 60 min=

mL

kg/min 100 mg 1000 mcg 2.2 lb 1 hr hr

46 mL 50 mg 1 hr 1000 mcg 2.2 lb �

mcg

hr 250 mL 60 min 1 mg 1 kg 160 lb kg/min

46 × 5 × 10 × 2.2 5060 �

2.1 or 2 mcg

25 × 6 × 1 × 16 2400 kg/min

500mg mL 50 � 10 mL

50 mg 5

5 mg 60 mL 1 kg 240 lb 60 min �

mL

kg/30 min 500 mg 2.2 lb 1 hr hr

5 × 6 × 24 × 6 4320 �

130.9 or 131 mL

3 × 5 × 2.2 33 hr

8 mcg 100 mL 1 mg 1 kg 198 lb 60 min�

mL

kg/min 100 mg 1000 mcg 2.2 lb 1 hr hr

8 × 1 × 198 × 6 9504 �

43.2 mL

100 × 2.2 220 hr

40 mg 5 mL 1 kg 80 lb day =

mL

kg/day 300 mg 2.2 lb 4 doses dose

4 × 5 × 1 × 8 160 �

6.06 or 6 mL

3 × 2.2 × 4 26.4 dose

45 mL 200 mg 1000 mcg 1 hr �

mcg

hr 500 mL 1 mg 60 min 60 kg kg/min

45 × 2 × 10 900 �

5 mcg

5 × 6 × 6 180 kg/min

2 mcg 500 mL 1 mg 60 min 1 kg 176 lb �

mL

kg/min 400 mg 1000 mcg 1 hr 2.2 lb hr

2 × 5 × 6 × 1 × 176 10,560 �

12 mL

4 × 100 × 2.2 880 hr

5 mcg 1 kg 130 lb 5 × 1 × 130 650 �

295.45 or 296 mcg

kg/day 2.2 lb 2.2 2.2 day


6

Sequential method:

9

Sequential method:

10

Sequential method:

7

Sequential method:

8

Sequential method:


0.5 mg 250 mL 1 kg 132 lb 0.5 × 1 × 132 66 �

30 mL

kg / hr 250 mg 2.2 lb 2.2 2.2 hr

2 mg mL 40 kg 2 × 4 8 �

8 mL

kg / day 10 mg 1 1 day

15 mL 200 mg 1 hr 1000 mcg 15×2 30 �

0.5 mcg

hr 1000 mL 60 min 1 mg 100 kg 60×1 60 kg/min

10 mL 300 mg 4 doses 2.2 lb �

mg

dose 5 mL day 1 kg 65 lb kg/day

10 × 300 × 4 × 2.2 26,400 �

81.23 or 81 mg

5 × 1 × 65 325 kg/day

25 mL 250 mg 25 �

0.5 mg

hr 250 mL 50 kg 50 kg/hr

11

12

13

10 mg 5 mL 1 kg 60 lb day 10 × 5 × 1 × 6 300 � 1.8 mL

kg/day 250 mg 2.2 lb 3 doses 25 × 2.2 × 3 165 dose

2 mL 250 mg 3 doses 2.2 lb 2 × 25 × 3 × 2.2 330 � 11 mg

dose 5 mL day 1 kg 60 lb 5 × 1 × 6 30 kg/day

3 mg 60 kg day 3 × 60 180 � 60 mgkg/day 3 doses 3 3 dose

60 mg 100 mL 60 min 100 � 100 mL

60 min 60 mg 1 hr 1 hr

14

7 mcg 250 mL 1 mg 80 kg 60 min 7 × 25 × 1 × 8 × 6 8400 � 16.8 or 17 mL

kg/min 500 mg 1000 mcg 1 hr 50 × 10 × 1 500 hr

15

16

17

18

19

20

15 mL 500 mg 1 hr 1000 mcg 15 × 50 × 1 × 10 7500 � 6.25 or 6 mcg

hr 250 mL 60 min 1 mg 80 kg 25 × 6 × 1 × 8 1200 kg/min

4 mg 250 mL 80 kg day 4 × 25 × 8 800 � 11.11 or 11 mL

kg/day 300 mg 24 hr 3 × 24 72 hr

20 mcg 1 kg 180 lb 1 mg 250 mL 60 min 2 × 1 × 18 × 1 × 25 × 6 5400 �

kg/min 2.2 lb 1000 mcg 400 mg 1 hr 2.2 × 10 × 4 × 1 88

61.36 or 61 mL

hr

30 mL 1 hr 400 mg 1000 mcg 2.2 lb 30 × 1 × 40 × 10 × 2.2 26400 �

hr 60 min 250 mL 1 mg 1 kg 180 lb 6 × 25 × 1 × 1 × 18 2700

9.7 or 10 mcg

kg/min

5 mcg 80 kg 60 min 1 mg 250 mL 5 × 8 × 6 × 1 × 25 6000 � 120 mL

kg/min 1 hr 1000 mcg 50 mg 1 × 10 × 5 50 hr

80 mL 50 mg 1 hr 1000 mcg 8 × 5 × 1 × 100 4000 � 3.33 or 3 mcg

hr 250 mL 60 min 80 kg 1 mg 25 × 6 × 8 × 1 1200 kg/min


Practice Problems

S E C T I O N 2

Practice Problems One-Factor Practice Problems


1. Order: trimethobenzamide HCl 200 mg qid IM for nausea and vomiting




For IM USE ONLY

20 mL Multi-Dose Vial

100 mg/mLStore between 15° and 30°C(59° and 86°F). Each mL ofsolution contains 100 mgtrimethobenzamidehydrochloride compoundedwith 0.45% pheol aspreservative. 0.5 mg sodiumcitrate and 0.2 mg citric acidas buffers, and sodiumhydroxide to adjust pH toapproximately 5.0Dosage: See accompanyingprescribing information.Caution: Federal lawprohibits dispensingwithout prescription. For IMuse only (preferably by deepIM injection).

LOT

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1 7 9

LWBK732_Sec02_p179-228:LWBK732 11/20/10 2:43 PM Page 179

2. Order: morphine 30 mg PO every 4 hours for pain


3. Order: prednisone 7.5 mg PO bid for inflammation


4. Order: acetaminophen 160 mg PO every 4 hours for fever


1 8 0 S E C T I O N 2 Practice Problems




1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY


5. Order: Xanax 0.5 mg PO tid for anxiety


6. Order: Adalat 60 mg PO daily for hypertension


7. Order: Halcion 0.25 mg PO at hs for insomnia


One-Factor Pract ice Problems 1 8 1


Courtesy of Miles Inc.




8. Order: furosemide 80 mg PO daily for congestive heart failure


9. Order: morphine sulfate 10 mg IM prn for pain






10. Order: naloxone HCl 100 mcg IVP prn for respiratory depression


11. Order: Solu-Medrol 80 mg IVP every 4 hours for inflammation







12. Order: lactulose 20 g PO daily for constipation


13. Order: prochlorperazine 5 mg IM tid for nausea and vomiting




2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

PROCHLORPERAZINE

as the edisylate INJECTION

10 mL Multi-Dose Vial

5 mg/mLStore below 86°F. Do notfreeze. Protect from light.Discard if markedlydiscolored. Each mL contains,in aqueous solution,prochlorperazine, 5 mg, asthe edisylate; sodiumbiphosphate, 5 mg; sodiumtartrate, 12 mg; sodiumsaccharin, 0.9 mg; benzylalcohol, 0.75%, as preservative.Dosage: For deep I.M. or I.V.injection. See accompanyingprescribing information.Caution: Federal lawprohibits dispensingwithout prescription.LO

TE

XP.


14. Order: amoxicillin/clavulanate potassium 250 mg PO every 8 hours for infection


15. Order: trimethobenzamide HCl 200 mg PO tid for nausea and vomiting

❊ How many capsules will you give? _____________

16. Order: prednisone 10 mg PO bid for adrenal insufficiency



1 × 5 mL(when reconstituted)

AMOXICILLIN/CLAVULANATE

POTASSIUM

FOR ORAL SUSPENSION

125 mg/mLPatient Starter

Package

Store dry powder at roomtemperature. After mixing,refrigerate, keep tightlyclosed and use within 24hours.Shake well before using.Directions for mixing: Tapbottle until all powder flowsfreely. Add approximately1 teaspoonful (5 mL) ofwater; shake vigorously.When reconstituted, each5 mL will contain 125 mgamoxicillin as the trihydrateand 31.25 mg clavulanicacid as clavulanatepotassium.U

se o

nly

if in

ner

seal

is in

tact

.C

auti

on

: Fe

dera

l law

pro

hibi

tsdi

spen

sing

with

out p

resc

riptio

n.

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2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

100 Capsules

TRIMETHO BENZAMIDE HCI

100 mg Store at room temperature.Container not for householduse. Dispense in a well-closedcontainer. Each capsulecontains 100 mgtrimethobenzamidehydrochloride.Dosage: See accompanyingprescribing information.Important: Use safety closureswhen dispensing this productunless otherwise directed byphysician or requested bypurchaser.

Cau

tio

n:

Fede

ral l

aw p

rohi

bits

disp

ensi

ng w

ithou

t pre

scrip

tion.

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EX

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17. Order: hydromorphone 3 mg IM every 4 hours for pain


18. Order: acetaminophen 400 mg PO every 4 hours prn for fever





2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12


19. Order: magnesium sulfate 1000 mg IM times four doses for

hypomagnesemia


20. Order: prochlorperazine 10 mg PO qid prn for nausea and vomiting




4 fl oz (118 mL)

PROCHLORPERAZINE as the

edisylate SYRUP

5 mg/5 mL Store at controlled room temperature(59°-86°F). Dispense in a tight,light-resistant glass bottle. Each 5 mL(1 teaspoon) contains prochlorperazine,5 mg, as the edisylate.Usual Dosage: Children; 5 to 15 mg daily.Adults: 10 to 30 mg daily. Seeaccompanying folder for completeprescribing information.Important: Use child-resistantclosures when dispensing thisproduct unless otherwise directedby physician or requested by purchaser.Caution: Federal law prohibits dispensingwithout prescription.

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2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12



21. Order: Hemabate 0.25 mg IM to control postpartum bleeding


22. Order: Lincocin 500 mg every 8 hours IV for infection

❊ How many milliliters will you draw from the vial? _____________


Courtesy of Pharmacia & Upjohn Company.



23. Order: Fragmin 2500 IU SQ daily for 10 days for thromboembolism

prophylaxis


24. Order: Vantin 200 mg every 12 hours PO for infection




2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12




25. Order: Cleocin 300 mg PO daily for P. carinii pneumonia

❊ How many capsules will you give? _____________

26. Order: Azulfidine 500 mg PO every 12 hours for management of

inflammatory bowel disease


27. Order: Mirapex 0.25 mg PO tid for signs/symptoms of idiopathic

Parkinson’s disease







28. Order: Glyset 25 mg PO tid at the start of each meal for management of type

2 diabetes mellitus


29. Order: Micronase 5 mg PO daily for control of blood sugars associated with

non–insulin-dependent diabetes mellitus


30. Order: Xanax 0.5 mg PO tid for panic attacks








31. Order: Depo-Provera 150 mg IM within the first 5 days of menses for con-

traception


32. Order: Eskalith 600 mg PO tid initial dose followed by 300 mg PO qid for treat-

ment of bipolar affective disorder. Check lithium levels every 3 months.




Courtesy of SmithKline Beecham Pharmaceuticals.


33. Order: Phenobarbital 60 mg PO bid for seizures

Supply: Phenobarbital Elixir 20 mg/5 mL


34. Order: Abacavir (Ziagen) 600 mg PO every day for HIV-1 infection in

combination with Zidovudine

Supply: Ziagen 300 mg/tablets


35. Order: Zidovudine 100 mg PO every four hours for symptomatic HIV

infection (600 mg/daily total)

Supply: Zidovudine 10 mg/mL syrup


Practice Problems Two-Factor Practice Problems


1. Order: digoxin elixir 25 mcg/kg for congestive heart failure



Two-Factor Pract ice Problems 1 9 3




2. Order: atropine sulfate 0.02 mg/kg IV every 4 hours for bradycardia



3. Order: lidocaine 2 mg/min IV for arrhythmia

Supply: lidocaine 2 g/500 mL D5W


4. Order: Mezlin 1.5 g IV every 4 hours for infection

Nursing drug reference: Reconstitute each 1 g with 10 mL of normal saline.

❊ How many milliliters will you draw from the vial alter reconstitution? _____________

5. Order: gentamicin 1 mg/kg IV every 8 hours for infection






Courtesy of Miles.


6. Order: morphine 15 mg/hr IV for intractable pain

Supply: morphine 300 mg/500 mL NS


7. Information obtained by the nurse: Dilaudid 50 mg in 250 mL NS is


❊ How many milligrams per houris the patient receiving? _____________

8. Order: add 10 mEq KCl to 1000 mL D5W

Supply: KCl 20 mEq/20 mL

❊ How many milliliters will you drawfrom the vial to add to the IV bag? _____________

9. Information obtained by the nurse: nitroglycerin 50 mg in 500 mL D5W is


❊ How many micrograms per minuteis the patient receiving? _____________

10. Information obtained by the nurse: 1000 mL D5W with 10 mEq KCl is infus-

ing at 100 mL/hr.

❊ How many milliequivalents of KCIis the patient receiving per hour? _____________

11. Order: infuse 1000 mL D5W at 250 mL/hr.



12. Order: infuse 750 mL NS over 5 hours



13. Order: infuse 500 mL D5W over 8 hours



14. Order: infuse 750 mL D5W







15. Order: infuse 250 mL NS




16. Order: infuse 1000 mL D5W/0.45% NS




17. Order: Fortaz 1.25 g IV every 12 hours for urinary tract infection

Supply: Fortaz 2-g vial

Nursing drug reference: Dilute each 1 g with 10 mL of sterile water and fur-

ther dilute in 100 mL 0.9% NS to infuse over 1 hour.


❊ Calculate the milliliters per hourto set the IV pump. _____________


18. Order: vancomycin 275 mg IV every 8 hours for infection


Nursing drug reference: Reconstitute each 500-mg vial with 10 mL NS and

further dilute with 250 mL NS to infuse over 1 hour.






19. Order: Mezlin 450 mg IV every 4 hours for infection

Supply: Mezlin 4-g vial

Nursing drug reference: Reconstitute each 1 g with 10 mL of sterile water and

further dilute in 100 mL NS to infuse over 30 minutes.




20. Order: gentamicin 23 mg IV every 8 hours for infection


Nursing drug reference: Dilute with 100 mL NS and infuse over 1 hour.




21. Order: Cortef 0.56 mg/kg PO daily for adrenal insufficiency

❊ How many milliliters will you give a child weighing 18 kg? _____________



1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY



22. Order: Colestid 30 g/day PO in four divided doses for hyper cholesterolemia

or management of cholesterol

❊ How many packets/dose will you give? _____________

23. Order: vincristine 10 mcg/kg IV weekly for treatment of Hodgkin’s

lymphoma

❊ How many milliliters will you give a patient weighing 50 kg? _____________





24. Order: cimetidine 1600 mg/day PO in two divided doses for gastro-esophageal

reflux disease

❊ How many tablets per dose will you give? _____________

25. Order: chlorpromazine 1 g/day PO in three divided doses for psychoses



30 TILTAB® Tablets

CIMETIDINE TABLETS

800 mg Store between 15° and 30°C (59°-86°F).Dispense in a tight,light-resistant container. Each Tiltab®tabletcontains cimetidine, 800 mg.Dosage: See accompanying prescribinginformation.Important: Use safety closures whendispensing this product unless otherwisedirected by physician or requested bypurchaser.Caution: Federal law prohibits dispensingwithout prescription.

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8 fl oz (237 mL)

CHLORPROMAZINE HCI

CONCENTRATE

Intended for Institutional Use

100 mg/mL Store between 15° and 30°C(59°-86°F).Important: Dispense in a tight,light-resistant glass bottle withgraduated child-resistant dropper.Nerve dispense in a flint, green orblue bottle. Bulk dilution for storageis not recommended.Each mL contains chlorpromazinehydrochloride, 100 mg.Usual Dosage: 75 to 400 mg daily.(Doses of 100 mg or more b.i.d. ort.i.d. are for use only in severeneuropsychiatric conditions.)The concentrate is, mg for mgtherapeutically equivalent to otheroral dosage forms of the drug.See accompanying prescribinginformation.Caution: Federal law prohibitsdispensing without prescription.

PHARMACIST: DO NOTREMOVE THIS PANELrtan

PATIENT INFORMATION

Caution: Avoid direct contact withskin or clothes because of thepossibility of contact dermatitis(skin reaction). Wash thoroughlyor change clothes if directcontact occurs.Dilute each dosebefore administration.Add dose to 60 mL (2 fl oz) ormore of tomato or fruit juice,milk, simple syrup, orangesyrup, carbonated beverages,coffee, tea or water.Dropper is graduatedin 25 mg increments from100 mg to 200 mg. To deliver25 mg or 50 mg dose, filldropper to 200 mg mark anddispense to 175 mg or 150 mgmark, respectively.

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2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12



26. Order: lamivudine 4 mg/kg PO bid for treatment of HIV infection

❊ How many milliliters will you give a child weighing 20 kg? _____________

27. Order: Zofran 0.15 mg/kg IV 15 to 30 minutes before administration

of chemotherapy for prevention of nausea and vomiting

❊ How many milliliters will you give a patient weighing 160 lb? _____________


*Each 1 mL of aqueous solution containsondansetron 2 mg as ondansetron hydrochloridedihydrate; sodium chloride 9.0 mg; citric acidmonohydrate 0.5 mg and sodium citratedihydrate 0.25 mg as buffers.

See package insert for Dosage and Administration.Store between 2° and 30° C (36° and 86°F).Protect from light.

GlaxoSmithKlineResearch Triangle Park, NC 27709Made in England

Rev. 01/07

1 2 3 4 5 6 7 8 9

10m

L

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

ALCOHOL FREE

Rx only

Lamivudine oral solution

10 mg/mL

240 MLStore in tightly closed bottles at 25°C(77°F) (see USP Controlled RoomTemperature).

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Copyright GlaxoSmithKline. Used with permission


28. Order: lamivudine 2 mg/kg PO twice daily for treatment of HIV infection

❊ How many tablets will you give a patient weighing 40 kg? _____________

29. Order: Zovirax 20 mg/kg PO qid for 5 days for treatment of chickenpox

❊ How many tablets will you give a child weighing 20 lb? _____________

30. Order: Wellbutrin SR 450 mg/day PO in three divided doses for

treatment of depression



Lamivudine tablets

150 mg 60 TabletsRX only

Each tablet contains150 mg of lamivudine.

See package insert for Dosageand Administration.

Store in tightly closed bottles at25°C (77°F) (see USP ControlledRoom Temperature).

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150





31. Order: Zantac 2.4 g/day PO in four divided doses for treatment of

duodenal ulcer


32. Order: Zinacef 500 mg/day IV in two divided doses for urinary tract

infection



Zantac® 300(ranitidine hydrochloride)tablets, USP300 mg

300 mg 30 Tablets

NDC 0173-0393-40

LOT

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Usual Adult Dosage: One tablet dailyafter the evening meal, at bedtime,or as directed by a physician.See package insert for full prescribinginformation.Store between 15° and 30°C (59°and 86°F) in a dry place. Protect from light.Replace cap securety after each opening.

Zantac is a registered trademark ofWarner-Lambert Company, usedunder license.

Each tablet contains300 mg of ranitidineas ranitidinehydrochloride.

GlaxoSmithKlineResearch Triangle Park, NC 277094133749

0173

-039

3-40

Rev. 6/01

Zantac

300




33. Order: Ceftazidime 1000 mg/day IV in two divided doses for treatment of res-

piratory tract infection

Nursing drug reference: Dilute each 1-g vial with 10 mL of normal saline.


34. Order: Gantrisin 150 mg/2.2 lb PO divided into 5 doses given over

24 hours for urinary tract infection



35. Order: Abacavir (Ziagen) 8 mg/kg PO bid for HIV-1 infection in

combination with Zidovudine

Supply: Ziagen 20 mg/mL oral solution




2 g

Ceftazidime for injectionL-arginine formulation

FOR PATIENTS 12 YRS.AND OLDER

Equivalent to 2 g of ceftazidime.

Rx only

IV Infusion Pack

LOT

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See package insert for Dosage and Administration.

Before constitution, store between 15° and 30°C (59° and 86°F)and protect from light.NOTE: Ceftazidime for injection dissolves withoutthe evolution of gas.

To prepare IV infusion solution, add 100 mL of an approveddiluent. After constitution, solutions maintain potency for 24hours at room temperature (not exceeding 25°C [77°F]) orfor 7 days under refrigeration. Constituted solutions may befrozen. See package insert for details. Color changes do notaffect potency. This vial contains 349 mg of L-arginine pergram of ceftazidime.

1 2 3 4 5 6 7 8 9

10m

L


Practice Problems Three-Factor Practice Problems


1. Order: cimetidine 40 mg/kg/day PO in four divided doses for treatment of

active ulcer




2. Order: furosemide 4 mg/kg/day IV for management of hypercalcemia of

malignancy





Single-Dose Unit

300 mg/5 mL

Each 5 mL dose containscimetidine hydrochlorideequivalent to cimetidine,300 mg; alcohol, 2.8%.Caution: Federal lawprohibits dispensingwithout prescription.

LOT

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3. Order: Cleocin 30 mg/kg/day IV in divided doses every 8 hours

for infection




4. Information obtained by the nurse: A child is receiving 0.575 mL/dose of gen-

tamicin IV every 8 hours from a supply of gentamicin 40 mg/mL.


❊ How many milligrams per kilogram per day is the patient receiving? _____________

5. Information obtained by the nurse: A child is receiving 0.125 mL/dose of

diphenhydramine (Benadryl) IV every 8 hours from a supply of

Benadryl 50 mg/mL.


❊ How many milligrams per kilogram per day is the child receiving? _____________

Three-Factor Pract ice Problems 2 0 5





Supply: dopamine 400-mg vial

Nursing drug reference: Dilute each 400-mg vial in 250 mL NS




7. Order: Nipride 0.8 mcg/kg/min IV for hypertensive crisis

Supply: Nipride 50 mg/500 mL NS



8. Information obtained by the nurse: Nipride 50 mg in 250 mL NS is




9. Order: Hydrea 30 mg/kg/day PO for ovarian carcinoma


❊ How many grams per day is the patient receiving? _____________




10. Order: Venoglobulin-S 0.01 mL/kg/min for treatment of

immunodeficiency syndrome



11. Information obtained by the nurse: dopamine 400 mg in 250 mL

D5W is infusing at 28 mL/hr.



12. Order: Inocor 3 mcg/kg/min IV for congestive heart failure

Supply: Inocor 100 mg/100 mL of 0.9% NS



13. Order: Nipride 2 mcg/kg/min




14. Order: Nipride 1 mcg/kg/min IV for hypertensive crisis



❊ Calculate the milliliters per hour to set the IV pump.

15. Order: dopamine 2.5 mcg/kg/min IV for hypotension

Supply: dopamine 400 mg/500 mL D5W






16. Information obtained by the nurse: Isuprel 2 mg in 500 mL D5W is



❊ How many micrograms per kilogram per minute is the child receiving? _____________

17. Order: Intropin 5 mcg/kg/min IV for treatment of oliguria after shock

Supply: Intropin 400 mg/500 mL NS


❊ Calculate the milliliters per minute. _____________

18. Order: vancomycin 40 mg/kg/day IV in three divided doses for infection


Nursing drug reference: Reconstitute each 500-mg vial with 10 mL sterile

water and further dilute in 100 mL of 0.9% NS to infuse over 60 minutes.


❊ How many milligrams per day is the child receiving? _____________

❊ How many milligrams per dose is the child receiving? _____________



19. Order: gentamicin 2 mg/kg/dose IV every 8 hours for infection

Supply: gentamicin 40-mg/mL vial

Nursing drug reference: Further dilute in 50 mL NS and infuse over

30 minutes.







20. Order: Cefazolin 25 mg/kg/day IV every 8 hours for infection

Supply: Cefazolin 500-mg vial

Nursing drug reference: Reconstitute each 500-mg vial with 10 mL of sterile

water and further dilute in 50 mL NS to infuse over 30 minutes.



❊ How many milligrams per doseis the child receiving? _____________



21. Order: Amikacin (Amikin) 15 mg/kg/day IV in 2 equally divided doses every

12 hours for 10 days for gram-negative bacterial infection

Supply: Amikin 500 mg in 100 mL 0.9% Normal Saline to infuse over

60 minutes


❊ How many milligrams per day is the patient receiving? _____________

❊ How many milligrams per dose is the patient receiving? _____________


22. Order: dopamine (Intropin) 2 mcg/kg/minute IV for shock

Supply: dopamine 200 mg/250 mL D5W




STERILE CEFAZOLIN

SODIUM

(LYOPHILIZED)

500 mg Before reconstitution protectfrom light and store between15° and 30°C (59° and 86°F).Usual Adult Dosage: 250 mg to1 gram every 6 to 8 hours.See accompanying prescribinginformation.Reconstituted Ancef is stable 24hours at room temperature or 10days if refrigerated (5°C or 41°F).

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LWBK732_Sec02_p179-228:LWBK732 23/11/10 1:06 AM Page 209

23. Order: epoetin (Procrit) 150 units/kg/day three times a week for

chemotherapy-induced anemia

Supply: Procrit 10,000 units/mL



24. Order: esmolol hydrochloride 500 mcg/kg/min for 1 minute then

50 mcg/kg/min for 4 minutes for supraventricular tachycardia in atrial fibril-

lation. Repeat after 5 minutes if SVT continues.

Supply: esmolol 2.5 g/250 mL D5W


❊ Calculate the milliliters per hour to set the IV pump for the oneminute administration. _____________

❊ Calculate the milliliters per hour to set the IV pump for thefour minute administration. _____________

25. Order: prednisone 0.1 mg/kg/day for chronic obstructive pulmonary disease.

Supply: prednisone 5 mg/5 mL oral solution


❊ How many milliliter per day will you give? _____________

Practice Problems Comprehensive Practice Problems


1. Order: digoxin 0.125 mg PO daily for congestive heart failure

On hand: digoxin 0.25 mg/tablet


2. Order: ascorbic acid 0.5 g PO daily for supplemental therapy

On hand: ascorbic acid 500 mg/tablet


3. Order: atropine gr 1/150 IM for on-call preanesthesia

Supply: atropine 0.4 mg/mL


4. Order: Mycostatin oral suspension 500,000 units swish-and-swallow for oral

thrush

On hand: Mycostatin 100,000 units/mL




5. Order: Demerol 50 mg IM every 4 hours for pain

Supply: Demerol 100 mg/mL


6. Order: vancomycin 2 mg/kg IV every 12 hours for infection

Supply: vancomycin 500 mg/10 mL



7. Order: ampicillin 2 mg/kg PO every 8 hours for infection

Supply: ampicillin 500 mg/5 mL



8. Order: 1000 mL D5W to infuse in 12 hours



9. Order: 500 mL D5W



❊ Calculate the hours to infuse. _____________

10. Order: heparin 1500 units/hr

Supply: 250-mL IV bag of D5W with 25,000 units of heparin


11. Order: 1000 mL NS IV



❊ Calculate the hours to infuse. _____________

12. Order: regular insulin 8 units per hour IV for hyperglycemia

Supply: 250 mL NS with 100 units of regular insulin


13. Order: 500 mL of 10% lipids to infuse in 8 hours



Comprehensive Pract ice Problems 2 1 1



14. Order: KCl 2 mEq/100 mL of D5W for hypokalemia

On hand: 20 mEq/10-mL vial

Supply: 500 mL D5W

❊ How many milliliters of KClwill you add to the IV bag? _____________

15. Order: aminophylline 44 mg/hr IV for bronchodilation

Supply: 250 mL D5W with 1 g of aminophylline


16. Order: Dilaudid 140 mL/hr

Supply: 1000 mL D5W/NS with 30 mg of Dilaudid

❊ Calculate the milligrams per hour that the patient is receiving. _____________

17. Order: Staphcillin 750 mg IV every 4 hours for infection

Supply: Staphcillin 6 g

Nursing drug reference: Reconstitute with 8.6 mL of sterile water to yield

500 mg/mL and further dilute in 100 mL of NS to infuse over 30 minutes.




18. Order: Pipracil 1.5 g every 6 hours for uncomplicated urinary tract infection

Supply: Pipracil 3-g vial

Nursing drug reference: Reconstitute each 3-g vial with 5 mL of sterile water

and further dilute in 50 mL of 0.9% NS to infuse over 20 minutes.







Supply: 250 mL D5W with 400 mg of dopamine



20. Order: Nipride 0.8 mcg/kg/min IV for hypertension

Supply: 500 mL D5W with 50 mg Nipride



21. Order: ampicillin (Principen) 500 mg PO every 6 hours for

chronic infection

Supply: 250 mg/5 mL


22. Order: atenolol (Tenormin) 50 mg PO per day for hypertension

Supply: atenolol 100 mg tablets.


23. Order: amiodarone (Cordarone IV) 150 mg IV over 10 minutes

Supply: amiodarone 150 mg in 100 mL D5W


24. Order: azithromycin (Zithromax) 30 mg/kg PO once a day for

three days for otitis media.

Supply: azithromycin 100 mg/5 mL



25. Order: amoxicillin 45 mg/kg/day in two divided doses for severe ear infection.

Supply: amoxicillin 400 mg/5 mL





Comprehensive Pract ice Problems 2 1 3


One-Factor Practice Problems

1

Sequential method:

2

Sequential method:

3

Sequential method:

4

Sequential method:

5

Sequential method:

6

Sequential method:

7

Sequential method:

8

Sequential method:

9

Random method:

10

Random method:

11

Sequential method:

Answer Key 2 1 5

ANSWER KEY FOR SECTION 2: PRACTICE PROBLEMS

200 mg mL 22 mL

100 mg 1

3 mL

30 mg tablet 31 tablet

30 mg 3�

7.5 mg tablet 7.53 tablets

2.5 mg 2.5�

160 mg 5 mL 1 tsp 11 tsp

160 mg 5 mL�

60 mg tablet1 tablet

60 mg�

80 mg tablet 84 tablets

20 mg 2�

10 mg mL 1 gr 1 1 1 1

1–8

gr 60 mg 1–8

6–1

6–8

0.75�

�

�

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY

0.5 mg tablet 0.50.5 tablet

1 mg 1�

0.25 mg tablet 0.252 tablets

0.125 mg 0.125�

3 mL

100 mcg mL 1 mg 1 × 1 1

0.4 mg 1000 mcg 0.4 × 10 4�

3 mL

80 mg 2 mL 80 2 1601.28 or 1.3 mL

125 mg 125 125�

�

3 mL

1.33 or 1.3 mL

0.25 or 0.3 mL

�


16

Sequential method:

17

Sequential method:

18

Sequential method:

19

Random method:

12

Sequential method:

13

Sequential method:

14

Sequential method:

15

Sequential method:

20 g 15 mL 2 15 3030 mL

10 g 1 1�

�

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

5 mg mL1 mL

5 mg�

mL

250 mg 5 mL 250 5 125010 mL

125 mg 125 125�

�

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

200 mg capsules 22 capsules

100 mg 1�


5 mg 5�

3 mg mL 31.5 mL

2 mg 2�

mL

400 mg 10.15 mL 400 10.15 4060

325 mg 325 325�

� 12.49 or12.5 mL

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

1000 mg 2 mL 1 g 2 1 22 mL

1 g 1000 mg 1 1�

�

mL



10 mg 5 mL 1 tsp 10 1 102 tsp

5 mg 5 mL 5 5�

�

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

0.25 mg mL 1000 mcg 0.25 100 251 mL

250 mcg 1 mg 25 1 25�

�

�

mL

500 mg mL 51.66 or 1.7 mL

300 mg 3�

mL

2500 IU 0.2 mL 0.2 0.2 mL

2500 IU�

mL

200 mg 5 mL 20 5 10020 mL

50 mg 5 5�

�

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

300 mg capsule 302 capsules

150 mg 15�

500 mg tablets 5001 tablet

500 mg 500�

0.25 mg tablets 0.252 tablets

0.125 mg 0.125�

25 mg tablets 250.5 tablet

50 mg 50�

5 mg tablets 52 tablets

2.5 mg 2.5�

0.5 mg tablets 0.52 tablets

0.25 mg 0.25�

20

Sequential method:

21

Random method:

22

Sequential method:

23

Sequential method:

24

Sequential method:

25

Sequential method:

26

Sequential method:

27

Sequential method:

28

Sequential method:

29

Sequential method:

30

Sequential method:

Answer Key 2 1 7


150 mg mL 150.375 or 0.4 mL

400 mg 40�

600 mg tablets 62 tablets

300 mg 3�

25 mcg 2.5 mL 1 kg 1 mg 25 lbmL

kg 0.125 mg 2.2 lb 1000 mcg�

25 2.5 1 1 25 1562.55.68 or 5.7 mL

0.125 2.2 1000 275�

� � � �

� �

0.02 mg mL 1 kg 35 lb 0.02 1 35 0.7

kg 0.1 mg 2.2 lb 0.1 2.2 0.22�

� �

�

3.18 or3.2 mL

2 mg 500 mL 1 g 60 min 5 6 30 30 mL

min 2 g 1000 mg 1 hr 1 1 hr�

�

1.5 g 10 mL 1.5 10 1515 mL

1 g 1 1�

�

15 mg 500 mL 15 5 75

hr 300 mg 3 3�

� 25 mL

hr

25 mL 50 mg 5

hr 250 mL�

5 mg

hr

10 mEq 20 mL 1010 mL

20 mEq�

100 mL 10 mEq 1 1 mEq

hr 1000 mL hr�

250 mL 20 gtt 1 hr 250 2 1 500 83.3 or 83 gtt

hr mL 60 min 6 6 min�

� �

3 mL 50 mg 1000 mcg 1 hr 3 10 30�

5 mcg

hr 500 mL 1 mg 60 min 6 6 min

�

1 mg mL 1 kg 94 lb 1 1 94 94

kg 40 mg 2.2 lb 40 2.2 88�

�

�

� 1.068 or1.1 mL

mL

60 mg 5 mL 6 5 3015 mL

20 mg 2 2�

�


300 mg 3�

100 mg mL 1010 mL

10 mg 1�

31

Sequential method:

32

Sequential method:

33

Sequential method:

34

Sequential method:

35

Sequential method:

Two-Factor Practice Problems

1

Random method:

2

Sequential method:

3

Random method:

4

Sequential method:

5

Sequential method:

6

Sequential method:

7

Sequential method:

8

Sequential method:

9

Sequential method:

10

Sequential method:

11

Sequential method:



750 mL 10 gtt 1 hr 750 1 1 750 25 gtt

5 hr mL 60 min 5 6 30 min�

� �

�

500 mL 60 gtt 1 hr 500 1 500 62.5 or 63 gtt

8 hr mL 60 min 8 8 min�

�

750 mL 15 gtt min 1 hr 750 15 1 11250 10.41 or

mL 18 gtt 60 min 18 60 1080�

� �

�10 hr

250 mL 15 gtt min 1 hr 25 15 1 3751.25 or

mL 50 gtt 60 min 50 6 300�

� �

� 1 hr

1000 mL 15 gtt min 1 hr 100 15 1 150010 hr

mL 25 gtt 60 min 25 6 150�

� �

�

1.25 g 10 mL 1.25 10 12.5 12.5 mL

1 g 1 1�

�

112.5 mL112.5 or

113 mL

hr hr�

112.5 mL 10 gtt 1 hr 112.5 1 1 112.5 18.75 or 19 gtt


� �

275 mg 10 mL 275 1 275 5.5 mL

500 mg 50 50�

�

255.5 mL 255.5 or

256 mL

hr hr�

255.5 mL 10 gtt 1 hr 255.5 1 1 255.5 42.5 or 43 gtt


� �

450 mg 10 mL 1 g 45 1 45 4.5 mL

1 g 1000 mg 10 10�

�

104.5 mL 60 min 104.5 6 627 209 mL

30 min 1 hr 3 1 3 hr�

�

�

104.5 mL 10 gtt 104.5 1 104.5 34.8 or 35 gtt

30 min mL 3 3 min�

�

12

Sequential method:

13

Sequential method:

14

Sequential method:

15

Sequential method:

16

Sequential method:

17

How many milliliters will you draw from the vial afterreconstitution?Sequential method:

Calculate the milliliters per hour to set the IV pump.Sequential method:

Calculate the drops per minute with a drop factor of10 gtt/mL.Sequential method:

18

How many milliliters will you draw from the vialafter reconstitution?Sequential method:



19

How many milliliters will you draw from the vial afterreconstitution?Random method:



Answer Key 2 1 9


100.6 mL100.6 or

101 mL

hr hr�

23 mg mL 230.57 or 0.6 mL

40 mg 40�

100.6 mL 15 gtt 1 hr 100.6 15 1 1509 25.15 or 25 gtt


� �

0.56 mg 18 kg 5 mL 0.56 18 5 50.45.04 or 5 mL

kg 10 mg 10 10�

� �

1

11 4 1 2 3 4

2 3 4 5 6 7 8 9 102 tsp

ml

1 1 11 4 1 2 3 4

OR

AL

ME

DIC

ATIO

NO

NLY

30 g day packet 30 30 1.5 packet

day 4 doses 5 g 4 5 20 dose�

�

10 mcg 2 mL 50 kg 1 mg 1 2 5 1 100.5 mL

kg 2 mg 1000 mcg 2 10 20�

� � �

�

mL

1600 mg tablets day 16 16 1 tablet

day 800 mg 2 doses 8 2 16 dose�

�

1 g mL 1000 mg day 10 10 3.33

day 100 mg 1 g 3 doses 1 3 or 3 mLdose

��

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

4 mg mL 20 kg 4 2 88 mL

kg 10 mg 1 1�

�

2 TBSP

1 TBSP

1 TSP

1 fl oz=30 mL

25 mL

20 mLfl oz=15 mL

10 mL

5 mL

12

0.15 mg mL 1 kg 160 lb 0.15 1 160 245.45 or

kg 2 mg 2.2 lb 2 2.2 4.4

��

� 5.5 mL

1 2 3 4 5 6 7 8 9

10m

L

20

How many milliliters will you draw from the vial?Sequential method:


Calculate the drops per minute with a drop factor of15 gtt/mL.

21

Sequential method:

22

Random method:

23

Random method:

24

Sequential method:

25

Random method:

26

Sequential method:

27

Sequential method:



2 mg tablets 40 kg 2 4 8 0.533 or

kg 150 mg 15 15 0.5 tablet�

�

20 mg tablet 1 kg 20 lb 2 1 2 4

kg 400 mg 2.2 lb 4 2.2 8.8�

� �

�

0.45 or

0.5 tablet

450 mg tablet day 45 45

day 150 mg 3 doses 15 3 45�

�

1 tablet

dose

500 mg 8 mL day 50 8 400

day 750 mg 2 doses 75 2 150�

�

�

2.666 or

2.7 mLdose

mL

2.4 g tablet day 1000 mg 2.4 10 24

day 300 mg 4 doses 1 g 3 4 1 12�

�

� �

2 tablets

dose

1000 mg 20 mL 1 g day 20 1 20

day 2 g 1000 mg 2 doses 2 2 4�

�

�

5 mL

dose

1 2 3 4 5 6 7 8 9

10m

L

150 mg 1 tsp 2.2 lb 30 kg 5 mL mL

2.2 lb/5 doses 500 mg 1 kg 1 tsp dose�

15 3 45 9 mL

5 1 5 dose�

�

�

8 mg mL 40 kg 8 4 3216 mL

kg 20 mg 2 2�

�

40 mg 5 mL 60 kg 4 5 6 120

kg/ day 300 mg 3 3�

� � 40 mL

day

40 mg 5 mL 60 kg day 4 5 6 120

kg/day 300 mg 4 doses 3 4 12�

�

� � 10 mL

dose

4 mg mL 1 kg 60 lb 4 1 6 24

kg/day 10 mg 2.2 lb 1 2.2 2.2�

� �

�

10.9 or 11 mL

day

30 mg 2 mL 50 kg day 2 5 10

kg/day 300 mg 3 doses 3 3�

� 3.33 or 3.3 mL

dose

30 mg 2 mL 50 kg 2 5 10

kg/ day 300 mg�

� 10 mL

day

28

Sequential method:

29

Sequential method:

30

Sequential method:

31

Random method:

32

Sequential method:

33

Random method:

34

Sequential method:

35

Sequential method:

Three-Factor Practice Problems

1

How many milliliters per day will you give?Sequential method:

How many milliliters per dose will you give?Sequential method:

2

Sequential method:

3

How many milliliters per day will you give?Sequential method:

How many milliliters per dose will you give?Sequential method:

Answer Key 2 2 1


0.575 mL 40 mg 2.2 lb 3 doses

dose mL 1 kg 45 lb day�

mg

kg/day

0.575 × 40 × 2.2 × 3 151.8

1 × 45 45�

3.37 or 3.4 mg

kg/day

0.125 mL 50 mg 2.2 lb 3 doses

dose mL 1 kg 20 lb day�

mg

kg/day

0.125 5 2.2 3 4.125

1 2 2�

��

�

2.06 or 2.1 mg

kg/day

400 mg 10 mL 1010 mL

400 mg�

5 mcg 260 mL 1 mg 1 kg 110 lb 60 min

kg/min 400 mg 1000 mcg 2.2 lb 1 hr �

mL

hr

5 26 1 11 6 8580

4 100 2.2 880�

� � � �

��

9.75 or 9.8 mL

hr

0.8 mcg 500 mL 1 mg 1 kg 60 min 143 lb

kg/min 50 mg 1000 mcg 2.2 lb 1 hr�

0.8 5 1 6 143 3432 31.2 mL

5 10 2.2 110 hr�

��

� �

mL

hr

0.01 mL 1 kg 180 lb 60 min 0.01 1 180 60

kg/min 2.2 lb 1 hr 2.2 1

� � �

�

68 5 1 2.2 10 7480 1.99 or 2 mcg

25 6 1 1 25 3750 kg/min�

� � � �

� � � �

30 mg 1 kg 157 lb 1 g 3 1 157 1 471

kg/ day 2.2 lb 1000 mg 2.2 × 100 220

��

108 49.09 or 49.1 mL

2.2 hr

�

28 4 1 1000 112,000 49.77 or 49.8 mcg

25 15 6 1 2250 kg/min�

� � �

� � �

2.14 or 2.1 g

day

68 mL 50 mg 1 hr 2.2 lb 1000 mcg

hr 250 mL 60 min 1 kg 1 mg 250 lb�

mcg

kg/min

28 mL 400 mg 1 hr 1000 mcg

hr 250 mL 15 kg 60 min 1 mg�

mcg

kg/min

3 1 6 16 1 288 13.09 or 13.1 mL

2.2 1 10 22 hr�

� � � �

� �

3 mcg 100 mL 1 kg 60 min 160 lb 1 mg

kg/min 100 mg 2.2 lb 1 hr 1000 mcg�

mL

hr

2 mcg 250 mL 1 kg 250 lb 1 mg 60 min

kg/min 50 mg 2.2 lb 1000 mcg 1 hr

2 25 1 25 6 750068.1 or

68 mL

5 2.2 10 110 hr�

� � � �

� �

4

Sequential method:

5

Sequential method:

6


Calculate the milliliters per hour to set the IV pump.Random method:

7

Random method:

8

Sequential method:

9

Random method:

10

Random method:

11

Random method:

12

Random method:

13

Random method:



2.5 5 65 6 1 4875 12.18 or 12.2 mL

4 1 100 400 hr�

� � � �

��

1 mcg 250 mL 1 kg 60 min 160 lb 1 mg

kg/min 50 mg 2.2 lb 1 hr 1000 mcg�

mL

hr

1 25 6 16 2400 21.81 or 21.8 mL

50 2.2 110 hr�

� � �

�

2.5 mcg 500 mL 65 kg 60 min 1 mg

kg/min 400 mg 1 hr 1000 mcg�

mL

hr

15 mL 2 mg 1 hr 1000 mcg

hr 500 mL 60 min 20 kg 1 mg

mcg

kg/min�

15 2 1 1 30

5 6 20 1 600

� � �

��

0.05 mcg

kg/min�

40 mg 1 kg 20 lb 40 1 20 800

kg/ day 2.2 lb 2.2 2.2

� � 363.63 or 363.6 mg

day�

5 mcg 500 mL 70 kg 1 mg

kg/ min 400 mg 1000 mcg

mL

min�

5 5 7 1 175

4 100 400

� � �

�

0.4375 or 0.44 mL

min�

363.6 mg day 363.6

day 3 doses 3

121.2 mgdose�

121.2 mg 10 mL 121.2 10 1212

500 mg 500 500

�2.424 or 2.4 mL�

102.4 mL 60 min 102.4

60 min 1 hr 1�

102.4 mL

hr

2 mg 40 kg 2 40 80

kg/ dose

� 80 mg

dose�

52 mL 60 min 52 6 312

30 min 1 hr 3 1 3

�

�

104 mL

hr�

80 mg mL 8

40 mg 42 mL�

14

Random method:

15

Random method:

16

Random method:

17

Random method:

18

How many milligrams per day is the child receiving?Sequential method:

How many milligrams per dose is the child receiving?Sequential method:



19

How many milligrams per dose is the child receiving?Random method:



Answer Key 2 2 3


600 mg 200 mL 60 min 600 2 1200 240 mL

60 min 500 mg 1 hr 5 1 5 hr�

�

�

1200 mg day 1200 600 mg

day 2 doses 2 dose�

25 mg 25 kg 25 25 625 625 mg

kg/ day day�

�

20

How many milligrams per day is the child receiving?Sequential method:

How many milligrams per dose is the child receiving?Sequential method:



21

Sequential method:How many milligrams per day is the patient receiving?

How many milligrams per dose is the patient receiving?



625 mg day 625 208.33 or 208.3 mg


208.3 mg 10 mL 208.3 1 208.34.166 or 4.2 mL

500 mg 50 50�

�

54.2 mL 60 min 54.2 6 325.2 108.4 mL

30 min 1 hr 3 1 3 hr�

�

�

15 mg 80 kg 15 80 1200 1200 mg

kg/ day day�

�

2 mcg 250 mL 1 mg 60 min 1 kg 175 lb mL

kg/min 200 mg 1000 mcg 1 hr 2.2 lb hr�

2 25 1 6 175 52500 11.9 or 12 mL

20 100 2.2 4400 hr�

� � � �

��

150 units mL 80 kg 15 8 120 1.2 mL

kg/ day 10,000 units 100 100 day�

�

0.1 mg 5 mL 35 kg 0.1 35 3.5 mL

kg/ day 5 mg day�

�

500 mcg 250 mL 1 g 1 mg 90 kg 60 min mL

kg/min 2.5 g 1000 mg 1000 mcg 1 hr hr�

5 25 1 9 6 6750 270 mL

2.5 10 1 25 hr�

� �

� � � �

50 mcg 250 mL 1 g 1 mg 90 kg 60 min mL

kg/min 2.5 g 1000 mg 1000 mcg 1 hr hr�

5 25 1 9 6 6750 27 mL

2.5 10 10 250 hr�

� � � �

� �

22

Random method:

23

Sequential method:

24

Random method:Calculate the milliliters per hour to set the IV pump for the one minute administration.

Calculate the milliliters per hour to set the IV pumpfor the four minute administration.

25

Sequential method:


8

Sequential method:

9

Sequential method:

10

Sequential method:

11

Sequential method:

12

Sequential method:

13

Sequential method:

14

Random method:

Answer Key 2 2 5

500,000 units mL 1 tsp 5 1 5

100,000 units 5 mL 1 5 5

�

�1 tsp�

50 mg mL 5

100 mg 100.5 mL�

2 mg 10 mL 75 kg 2 1 75 150

kg 500 mg 50 50

� �3 mL�

2 mg

kg

5 mL

500 mg

1 kg 100 lb 2 5 1 1� � � 10

2.2 lb 5 2.2� 110.9 mL�

1000 mL

12 hr

15 gtt

mL

1 hr

60 min

100 15 1� �

12 6�

1500

72

20.8 or 21 gtt

min�

500 mL 15 gtt

mL

min

21 gtt

1 hr

60 min

50 15 1� �

21 6�

750

1265.9 hr�

1500 units

hr

250 mL

25,000 units

15 25�

25

375

25

15 mL

hr�

1000 mL 15 gtt

mL

min

50 gtt

1 hr

60 min

10 15 1� �

5 6�

150

305 hr�

8 units

hr

250 mL

100 units

8 25� 200 20 mL

hr�

10

1—150gr mL 60 mg 1—150

60–1

60—1500.4

1 mL0.4 mg 1 gr 0.4 1 0.4 0.4

��

�

0.125 mg tablet 0.125

0.25 mg 0.250.5 tablet�

0.5 g tablet 1000 mg 0.5 10 5

500 mg 1 g 5 1 5

�

�1 tablet�

10

500 mL 10 gtt 1 hr 50 10 1 500

8 hr mL 60 min 8 6 48�

� � 10.4 or 10 gtt

min�

2 mEq 10 mL 500 mL 2 1 5 10

100 mL 20 mEq 1 2 2

� �

�5 mL�

Comprehensive Practice Problems

1

Sequential method:

2

Random method:

3

Random method:

4

Sequential method:

5

Sequential method:

6

Sequential method:

7

Sequential method:


15

Random method:

16

Sequential method:

17




18




19

Random method:

20

Random method:

21

Sequential method:


4 25 1 6 1 12 7200 8.1 or 8 mL

40 10 1 2.2 880 hr�

� � � � �

� � �

44 mg 250 mL 1 g 44 25 1 1100

hr 1 g 1000 mg 1 100 100

� �

�

11 mL

hr�

140 mL 30 mg 14 3 42

hr 1000 mL 10 10

� 4.2 mg

hr�

101.5 mL 60 min 101.5 6 609 203 mL

30 min 1 hr 3 1 3 hr�

�

�

750 mg mL 751.5 mL

500 mg 50�

203 mL 10 gtt 1 hr 203 1 1 203 33.83 or 34 gtt


� �

52.5 mL 60 min 52.5 6 315 157.5 or 158 mL

20 min 1 hr 2 1 2 hr�

�

�

158 mL 20 gtt 1 hr 158 2 1 316 52.66 or 53 gtt


� �

4 mcg 250 mL 1 mg 60 min 1 kg 120 lb mL

kg/min 400 mg 1000 mcg 1 hr 2.2 lb hr�

1.5 g 5 mL 1.5 5 7.52.5 mL

3 g 3 3�

�

0.8 5 1 1 143 6 3432 31.2 or 31 mL

5 10 2.2 1 110 hr�

� � � � �

��

0.8 mcg 500 mL 1 mg 1 kg 143 lb 60 min mL

kg/min 50 mg 1000 mcg 2.2 lb 1 hr hr�

500 mg 5 mL 50 5 25010 mL

250 mg 25 25�

�


22

Sequential method:

23

Sequential method:

24

Sequential method:

25

Sequential method:How many milligrams per day is the child receiving?

How many milligrams per dose is the child receiving?

How many milliliters per dose will you give?

Answer Key 2 2 7

150 mg 100 mL 60 min 100 6 600 600 mL

10 min 150 mg 1 hr 1 1 1 hr�

�

�

50 mg tablets 50.5 tablet

100 mg 10�

30 mg 5 mL 15 kg 3 5 15 22522.5 or 23 mL

kg 100 mg 10 10�

� �

45 mg 35 kg 45 35 1575 1575 mg

kg/ day day�

�

1575 mg day 1575 787.5 787.5 or 788 mg


788 mg 5 mL 788 5 3940 9.85 or 10 mL

dose 400 mg 400 400 dose�

�


Case Studies

S E C T I O N 3

This section contains case studies simulating typical orders that might be written forpatients with selected disorders. In each case, the orders include multiple situationsthat require the nurse to perform clinical calculations before being able to implementthe order. After reading the short scenario, read through the list of orders.

Place a check mark in the box next to the physician’s order that probably requiresfurther calculations before implementing.

CASE STUDY 1 Congestive Heart Failure

A patient is admitted to the hospital with a diagnosis of dyspnea, peripheral edemawith a 10-lb weight gain, and a history of congestive heart failure. The orders fromthe physician include:

◗ Bed rest in Fowler’s position◗ O2 at 4 L/min per nasal cannula◗ Chest x-ray, complete blood count, electrolyte panel, BUN, serum creatinine

levels, and a digoxin level◗ IV of D5W/1–2 NS at 50 mL/hr◗ Daily AM weight◗ Antiembolism stockings◗ Furosemide 40 mg IV daily◗ Digoxin 0.125 mg PO daily◗ KCl 20 mEq PO tid◗ Low-Na diet◗ Restrict PO fluids to 1500 mL/day◗ Vitals every 4h◗ Accurate intake/output

Identify the orders that require calculations.2 2 9


Set up and solve each problem using dimensional analysis.

1. Calculate gtt/min using microtubing (60 gtt/mL).

2. Calculate the weight gain in kilograms.

3. Calculate how many mL of Lasix the patient will receive IV from a multidosevial labeled 10 mg/mL.

4. Calculate how many tablets of digoxin the patient will receive from a unit doseof 0.25 mg/tablet.

5. Calculate how many tablets of K-Dur the patient will receive from a unit doseof 10 mEq/tablet.

2 3 0 S E C T I O N 3 Case Studies

CASE STUDY 2 COPD/Emphysema

A patient is admitted to the hospital with dyspnea and COPD exacerbation. Theorders from the physician include:

◗ Stat ABGs, chest x-ray, complete blood count, and electrolytes◗ IV D5W/1–2 NS 1000 mL/8 hr◗ Aminophylline IV loading dose of 5.6 mg/kg over 30 minutes followed by

0.5 mg/kg/hr continuous IV◗ O2 at 2 L/min per nasal cannula◗ Albuterol respiratory treatments every 4h◗ Chest physiotherapy every 4h◗ Erythromycin 800 mg IV every 6h◗ Bed rest◗ Accurate intake/output◗ High-calorie, protein-rich diet in six small meals daily◗ Encourage PO fluids to 3 L/day

Identify the orders that require calculations.


1. Calculate mL/hr to set the IV pump.

2. Calculate mL/hr to set the IV pump for the loading dose of aminophylline for apatient weighing 140 lb. Aminophylline supply: 100 mg/100 mL D5W.

3. Calculate mL/hr to set the IV pump for the continuous dose of aminophyl line for apatient weighing 140 lb. Aminophylline supply: 1 g/250 mL D5W.

4. Calculate mL/hr to set the IV pump to infuse erythromycin 800 mg. Eryth -romycin supply: 1-g vial to be reconstituted with 20 mL sterile water and further diluted in 250 mL NS to infuse over 1 hr.

5. Calculate the PO fluids in mL/shift.


Case Studies 2 3 1

CASE STUDY 3 Small Cell Lung Cancer

A patient with small cell lung cancer is admitted to the hospital with fever and dehy-dration. The orders from the physician include:

◗ O2 at 2 L/min per nasal cannula◗ Chest x-ray; complete blood count; electrolytes; blood, urine, and sputum

cultures; BUN and serum creatinine levels; type and cross for 2 units of PRBCs

◗ IV D5W/1–2 NS 1000 mL with 10 mEq KCl at 125 mL/hr◗ 2 units of PRBCs if Hg is below 8◗ 6 pack of platelets if under 20,000◗ Neupogen 5 mcg/kg SQ daily◗ Gentamicin 80 mg IV every 8h◗ Decadron 8 mg IV daily◗ Fortaz 1 g IV every 8h◗ Accurate intake/output◗ Encourage PO fluids◗ Vitals every 4h (call for temperature above 102°F)



1. Calculate gtt/min using macrotubing (20 gtt/mL).

2. Calculate how many mcg of Neupogen will be given SQ to a patient weighing160 lb.

3. Calculate mL/hr to set the IV pump to infuse gentamicin. The vial is labeled 40 mg/mL and is to be further diluted in 100 mL D5W to infuse over 1 hr.

4. Calculate how many mL of Decadron the patient will receive from a viallabeled dexamethasone 4 mg/mL.

5. Calculate mL/hr to set the IV pump to infuse Fortaz 1 g over 30 minutes. Supply: Fortaz 1 g/50 mL.

CASE STUDY 4 Acquired Immunodeficiency Syndrome (AIDS)

A patient who is HIV+ and a Jehovah’s Witness is admitted to the hospital with ane-mia, fever of unknown origin, and wasting syndrome with dehydration. The ordersfrom the physician include:

◗ O2 at 4 L/min per nasal cannula◗ IV D5W/1–2 NS at 150 mL/hr



CASE STUDY 5 Sickle Cell Anemia

A patient is admitted to the hospital in sickle cell crisis. The orders from the physi-cian include:

◗ Bed rest with joint support◗ O2 at 2 L/min per nasal cannula◗ Complete blood count, erythrocyte sedimentation rate, serum iron levels, and

chest x-ray◗ IV D5W/1–2 NS at 150 mL/hr◗ Zofran 8 mg IV every 8h◗ Morphine sulfate 5 mg IV prn

◗ CD4 and CD8 T-cell subset counts; erythrocyte sedimentation rate; completeblood count; urine, sputum, and stool cultures; chest x-ray

◗ Acyclovir 350 mg IV every 8h◗ Neupogen 300 mcg SQ daily◗ Epogen 100 units/kg SQ three times a week◗ Megace 40 mg PO tid◗ Zidovudine 100 mg PO every 4h◗ Vancomycin 800 mg IV every 6h◗ Respiratory treatments with pentamidine◗ High-calorie, protein-rich diet in six small meals daily◗ Encourage PO fluids to 3 L/day◗ Accurate intake/output◗ Daily AM weight




2. Calculate mL/hr to set the IV pump to infuse acyclovir 350 mg. Supply: 500-mg vial to be reconstituted with 10 mL sterile water and further diluted in100 mL D5W to infuse over 1 hr.

3. Calculate how many mL of Neupogen will be given SQ. The vial is labeled 300 mcg/mL.

4. Calculate how many mL of Epogen will be given SQ to the patient weighing100 lb. The vial is labeled 4000 units/mL.

5. Calculate how many mL/hr to set the IV pump to infuse vancomycin 800 mg. Supply: 1-g vials to be reconstituted with 10 mL NS and further diluted in 100 mL D5W to infuse over 60 min.


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CASE STUDY 6 Deep Vein Thrombosis

A patient is admitted to the hospital with right leg erythema and edema to R/O DVT.The orders from the physician include:

◗ Bed rest with right leg elevated◗ Warm, moist heat to right leg with Aqua-K pad◗ Doppler ultrasonography◗ Partial thromboplastin time (PTT) and prothrombin time (PT)◗ IV D5W/1–2 NS with 20 mEq KCl at 50 mL/hr◗ Heparin 5000 units IV push followed by continuous IV infusion of

1000 units/hr◗ Lasix 20 mg IV bid◗ Morphine 5 mg IV every 4h



1. Calculate gtt/min using microtubing (60 gtt/mL).

2. Calculate how many mL of heparin the patient will receive IV from a multi dosevial labeled 10,000 units/mL.

3. Calculate mL/hr to set the IV pump for the continuous dose of heparin. Heparin supply: 25,000 units/250 mL D5W.

◗ Hydrea 10 mg/kg/day PO◗ Folic acid 0.5 mg daily PO◗ Encourage 3000 mL/daily PO




2. Calculate mL/hr to set the IV pump to infuse Zofran 8 mg. Supply: Zofran 8 mg in 50 mL D5W to infuse over 15 min.

3. Calculate how many mL of morphine sulfate will be given IV. The syringe islabeled 10 mg/mL.

4. Calculate how many mg/day of Hydrea will be given PO to the patient weighing 125 lb.

5. Calculate how many tablets of folic acid will be given PO. Supply: 1 mg/tablet.


4. Calculate how many mL of Lasix the patient will receive IV from a multidosevial labeled 10 mg/mL.

5. Calculate how many mL of morphine the patient will receive from a syringelabeled 10 mg/mL.


CASE STUDY 7 Bone Marrow Transplant

A patient is admitted to the hospital with a rash after an allogeneic bone marrowtransplant. The orders from the physician include:

◗ IV D5W/1–2 NS with 20 mEq KCl/L at 80 mL/hr◗ Complete blood count; electrolytes; sputum, urine, and stool cultures; blood

cultures ×3; liver panel; BUN; and creatinine◗ Vitals every 4h◗ Strict intake/output◗ Fortaz 2 g IV every 8h◗ Vancomycin 1 g IV every 6h◗ Claforan 1 g IV every 12h◗ Erythromycin 800 mg IV every 6h



1. Calculate how many mEq/hr of KCl the patient will receive IV.

2. Calculate mL/hr to set the IV pump to infuse Fortaz 2 g. Supply: Fortaz 2-gvial to be reconstituted with 10 mL of sterile water and further diluted in 50 mL D5W to infuse over 30 min.

3. Calculate mL/hr to set the IV pump to infuse vancomycin 1 g. Supply: van-comycin 500-mg vial to be reconstituted with 10 mL of sterile water and fur-ther diluted in 100 mL of D5W to infuse over 60 min.

4. Calculate mL/hr to set the IV pump to infuse Claforan 1 g. Supply: Claforan 600 mg/4 mL to be further diluted with 100 mL D5W to infuse over 1 hr.

5. Calculate mL/hr to set the IV pump to infuse erythromycin 800 mg. Supply:Erythromycin 1-g vial to be diluted with 20 mL sterile water and furtherdiluted in 250 mL of NS to infuse over 60 min.


Case Studies 2 3 5

CASE STUDY 8 Pneumonia

A patient is admitted to the hospital with fever, cough, chills, and dyspnea to ruleout pneumonia. The orders from the physician include:

◗ IV 600 mL D5W every 8h◗ Intake/output◗ Vitals every 4h◗ Complete blood count, electrolytes, chest x-ray, ABGs, sputum specimen,

blood cultures, and bronchoscopy◗ Bed rest◗ Humidified O2 at 4 L/min per nasal cannula◗ High-calorie diet◗ Encourage oral fluids of 2000 to 3000 mL/day◗ Pulse oximetry every AM

◗ Clindamycin 400 mg IV every 6h◗ Albuterol respiratory treatments◗ Guaifenesin 200 mg PO every 4h◗ Terbutaline 2.5 mg PO tid◗ MS Contrin 30 mg PO every 4h prn



1. Calculate mL/hr to set the IV pump to infuse clindamycin 400 mg. Supply: Clindamycin 600 mg/4 mL to be further diluted with 50 mL D5W to infuse over 1 hr.

2. Calculate gtt/min to infuse the clindamycin using macrotubing (20 gtt/mL).

3. Calculate how many mL of guaifenesin the patient will receive from a stockbottle labeled 30 mg/tsp.

4. Calculate how many tablets of terbutaline the patient will receive from a unitdose of 5 mg/tablet.

5. Calculate how many tablets of MS Contrin the patient will receive from a unitdose of 30 mg/tablet.

CASE STUDY 9 Pain

A patient is admitted to the hospital with intractable bone pain secondary toprostate cancer. The orders from the physician include:

◗ IV D5W/1–2 NS with 20 mEq KCl/L at 60 mL/hr◗ IV 500 mL NS with 25 mg Dilaudid and 50 mg Thorazine at 21 mL/hr◗ Heparin 25,000 units/250 mL D5W at 11 mL/hr



CASE STUDY 10 Cirrhosis

A patient is admitted to the hospital with ascites, stomach pain, dyspnea, and a his-tory of cirrhosis of the liver. The orders from the physician include:

◗ IV D5W/1–2 NS with 20 mEq KCl at 125 mL/hr◗ IV Zantac 150 mg/250 mL NS at 11 mL/hr◗ O2 at 2 L/min per nasal cannula◗ Type and crossmatch for 2 units of packed red blood cells, complete blood

count, liver panel, PT/PTT, SMA-12.◗ Carafate 1 g every 4h PO◗ Vitamin K 10 mg SQ every AM

◗ Spironolactone 50 mg PO bid◗ Lasix 80 mg IV every AM

◗ Measure abdominal girth every AM

◗ Sodium restriction to 500 mg/day◗ Fluid restriction to 1500 mL/day



1. Calculate the gtt/min using macrotubing (20 gtt/mL).

2. Calculate the mg/hr of Zantac the patient is receiving.

3. Calculate how many mL of vitamin K the patient will receive SQ from a unitdose labeled 10 mg/mL.

◗ Bed rest◗ Do not resuscitate◗ O2 at 2 L/min per nasal cannula◗ Bumex 2 mg IV every AM after albumin infusion◗ Albumin 12.5 g IV every AM



1. Calculate how many mEq/hr of KCl the patient is receiving.

2. Calculate how many mg/hr of Dilaudid the patient is receiving.

3. Calculate how many mg/hr of Thorazine the patient is receiving.

4. Calculate how many units/hr of heparin the patient is receiving.

5. Calculate how many mL of Bumex the patient will receive from a stock dose of0.25 mg/mL.


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CASE STUDY 11 Hyperemesis Gravidarum

A 14-year-old patient is admitted to the hospital with weight loss and dehydrationsecondary to hyperemesis gravidarum. The orders from the physician include:

◗ Bed rest with bathroom privileges◗ Obtain weight daily◗ Vital every 4h◗ Test urine for ketones◗ Urinalysis, complete blood count, electrolytes, liver enzymes, and bilirubin◗ NPO for 48 hr, then advance diet to clear liquid, full liquid, and as tolerated◗ IV D5 1–2 NS at 150 mL/hr for 8 hr, then decrease to 100 mL/hr◗ Observe for signs of metabolic acidosis, jaundice, or hemorrhage◗ Monitor intake and output◗ Droperidol (Inapsine) 1 mg IV every 4h prn for nausea◗ Metoclopramide (Reglan) 20 mg IV in 50 mL of D5W to infuse over

15 min◗ Diphenhydramine (Benadryl) 25 mg IV every 3h prn for nausea◗ Dexamethasone (Decadron) 4 mg IV every 6h



1. Calculate gtt/min using macrotubing (20 gtt/mL) to infuse 150 mL/hr, then 100 mL/hr.

2. Calculate how many mL of droperidol the patient will receive IV. Supply: 2.5 mg/mL

3. Calculate mL/hr to set the IV pump to infuse metoclopramide (Reglan) 20 mg in 50 mL of D5W to infuse over 15 min.

4. Calculate how many mL of diphenhydramine (Benadryl) the patient willreceive IV. Supply: 10 mg/mL.

5. Calculate how many mL of dexamethasone (Decadron) the patient will receive IV.Supply: 4 mg/mL.

4. Calculate how many tablets of spironolactone the patient will receive from aunit dose labeled 25 mg/tablet.

5. Calculate how many mL of Lasix the patient will receive from a unit doselabeled 10 mg/mL.



CASE STUDY 12 Preeclampsia

A nulliparous female is admitted to the hospital with pregnancy-induced hypertension. The orders from the physician include:

◗ Complete bed rest in left lateral position◗ Insert Foley catheter and check hourly for protein and specific gravity◗ Daily weight◗ Methyldopa (Aldomet) 250 mg PO tid◗ Hydralazine (Apresoline) 5 mg IV every 20 min for blood pressure over

160/100◗ Complete blood count, liver enzymes, chemistry panel, clotting studies, type

and crossmatch, and urinalysis◗ Magnesium sulfate 4 g in 250 mL D5LR loading dose to infuse over 30 min◗ Magnesium sulfate 40 g in 1000 mL LR to infuse at 1 g/hr◗ Keep calcium gluconate and intubation equipment at the bedside◗ Nifedipine (Procardia) 10 mg sublingual for blood pressure over 160/100 and

repeat in 15 min if needed.◗ Keep lights dimmed and maintain a quiet environment◗ Monitor blood pressure, pulse, and respiratory rate, fetal heart rate (FHR)

contractions every 15 to 30 min, and deep tendon reflexes (DTR) hourly◗ Monitor intake and output, proteinuria, presence of headache, visual distur-

bances, and epigastric pain hourly◗ Restrict hourly fluid intake to 100 to 125 mL/hr



1. Calculate how many tablets of methyldopa (Aldomet) will be given PO. Supply: 500 mg/tablet.

2. Calculate how many mL of hydralazine (Apresoline) will be given IV. Supply:20 mg/mL.

3. Calculate mL/hr to set the IV pump to infuse magnesium sulfate 4 g in 250 mL D5W loading dose to infuse over 30 min.

4. Calculate mL/hr to set the IV pump to infuse magnesium sulfate 40 g in 1000 mL LR to infuse at 1 g/hr.

5. Calculate how many capsules of nifedipine (Procardia) will be needed to givethe sublingual dose. Supply: 10 mg/capsule.

CASE STUDY 13 Premature Labor

A 35-year-old female in the 30th week of gestation is admitted to the hospital inpremature labor. The orders from the physician include:

◗ Bed rest in left lateral position◗ Monitor intake and output


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◗ Daily weights◗ Continuous fetal monitoring◗ Monitor blood pressure, pulse rate, respirations, fetal heart rate, uterine con-

traction pattern, and neurologic reflexes◗ Keep calcium gluconate at the bedside◗ Initiate magnesium sulfate 4 g in 250 mL LR loading dose over 20 min, then

2 g in 250 mL LR at 2 g/hr until contractions stop◗ Continue tocolytic therapy with terbutaline (Brethine) 0.25 mg SQ every

30 min for 2 hr after contractions stop◗ Give nifedipine (Procardia) 10 mg sublingual now, then 20 mg PO every 6h

after infusion of magnesium sulfate and contractions have stopped◗ Betamethasone 12 mg IM × 2 doses 12 hr apart◗ IV LR 1000 mL over 8 hr



1. Calculate mL/hr to set the IV pump to infuse the loading dose magnesium sul-fate 4 g in 250 mL LR over 20 min and the 2 g/hr maintenance dose.

2. Calculate how many mL of terbutaline (Brethine) will be given SQ. Supply: 1 mg/mL.

3. Calculate how many capsules of nifedipine (Procardia) will be given PO every 6h. Supply: 10 mg/capsule.

4. Betamethasone 12 mg IM × 2 doses 12 hr apart. Supply: 6 mg/mL.

5. Calculate mL/hr to set the IV pump to infuse LR 1000 mL over 8 hr.

CASE STUDY 14 Cystic Fibrosis

A 10-year-old child weighing 65 lb is admitted to the hospital with pulmonary exac-erbation. The orders from the physician include:

◗ Complete blood count with differential, ABGs, chest x-ray, urinalysis, chemistrypanel, and sputum culture

◗ IV 0.9% normal saline at 75 mL/hr◗ Daily weights◗ Monitor vitals every 4h◗ Oxygen at 2 L/min with pulse oximetry checks to maintain oxygen

saturation above 92%◗ Pancrease 2 capsules PO with meals and snacks◗ High-calorie, high-protein diet◗ Multivitamin 1 tablet PO daily



CASE STUDY 15 Respiratory Syncytial Virus (RSV)

A 2-year-old child weighing 30 lb is admitted to the hospital for severe respiratorydistress. The orders from the physician include:

◗ Complete blood count with differential, electrolytes, blood culture, chest x-ray,and nasal washing

◗ Humidified oxygen therapy to keep oxygen saturation >92%◗ Continuous pulse oximetry◗ IV D5W1–2 NS at 50 mL/hr◗ Elevate HOB◗ Vitals every 2h◗ Contact isolation◗ Cardiorespiratory monitor◗ Strict intake and output with urine specific gravities◗ Acetaminophen elixir 120 mg every 4h prn for temperature above 101°F◗ Aminophylline loading dose of 5 mg/kg to infuse over 30 min and maintenance

dose of 0.8 mg/kg/hr

◗ Tagamet 30 mg/kg/day PO in four divided doses with meals and HS with asnack.

◗ Clindamycin 10 mg/kg IV every 6h◗ Postural drainage and percussion after aerosolized treatments◗ Albuterol treatments with 2 inhalations every 4h to 6h◗ Terbutaline PO 2.5 mg every 6h◗ Tobramycin 1.5 mg/kg every 6h◗ Tobramycin peak and trough levels after fourth dose




2. Calculate how many tablets of Tagamet will be given PO with meals and HSsnack. Supply: 200 mg/tablet.

3. Calculate how many mg of clindamycin the patient will receive, how many mLto draw from the vial, and mL/hr to set the IV pump. Supply: 150 mg/mL vialto be further diluted in 50 mL of NS and infused over 20 min.

4. Calculate how many tablets of terbutaline will be given PO. Supply: 2.5 mg/tablet.

5. Calculate how many mg of tobramycin the patient will receive, how many mLto draw from the vial, and mL/hr to set the IV pump. Supply: 40 mg/mL vial tobe further diluted in 50 mL of NS and infused over 30 min.


Case Studies 2 4 1

◗ Ribavirin (Virazole) inhalation therapy × 12 hr/day◗ NPO with respiratory rate above 60◗ RespiGam 750 mg/kg IV monthly◗ Pediapred 1.5 mg/kg/day in three divided doses◗ Ampicillin 100 mg/kg/day in divided doses every 6h



1. Calculate how many mL of acetaminophen elixir the patient will receive. Supply: 120 mg/5 mL.

2. Calculate how many mg of aminophylline the patient will receive and the mL/hrto set the IV pump for the loading dose, then calculate the mL/hr to set the IVpump for the maintenance dose. Supply: 250 mg/100 mL.

3. Calculate how many mg of RespiGam the patient will receive IV on a monthlyinfusion.

4. Calculate how many mL/dose of Pediapred the patient will receive. Supply: 15 mg/5 mL.

5. Calculate how many mg/dose of ampicillin the patient will receive IV, how many mL to draw from the vial, and mL/hr to set the IV pump. Supply: 1-g vials to be diluted with 10 mL of NS and further diluted in 50 mL NS toinfuse over 30 min.

CASE STUDY 16 Leukemia

A 14-year-old child is admitted to the hospital with fever of unknown origin (FUO)after chemotherapy administration. The orders from the physician include:

◗ Complete blood count with differential, bone marrow aspiration, chemistrypanel, PT/PTT, blood cultures, urinalysis, and type and crossmatch

◗ Regular diet as tolerated◗ Vitals every 4h◗ Daily weights◗ Monitor intake and output◗ Type and cross for 2 units PRBCs◗ Irradiate all blood products◗ Infuse 6 pack of platelets for counts under 20,000◗ IV D5W/NS with 20 mEq KCl 1000 mL/8 hr◗ Allopurinol 200 mg PO tid◗ Fortaz 1 g IV every 6h◗ Aztreonam (Azactam) 2 g IV every 12h



CASE STUDY 17 Sepsis

A neonate born at 32 weeks’ gestation (weight 2005 g) is admitted to the NeonatalIntensive Care Unit (NICU) with a diagnosis of sepsis. The orders from the physi-cian include:

◗ Admit to NICU with continuous cardiorespiratory monitoring◗ Complete blood counts, blood and urine cultures, chest x-ray, bilirubin,

ABGs, theophylline levels, and lumbar puncture◗ Strict intake and output◗ Daily weight◗ Vitals every 3h◗ NG breast milk diluted with sterile water 120 mL/day with feedings every 3h◗ IV D10 and 20% lipids 120 mL/kg/day◗ Aminophylline 5 mg/kg IV every 6h◗ Cefotaxime (Claforan) 50 mg/kg every 12h◗ Vancomycin 10 mg/kg/dose every 12h



1. Calculate how many mL the child will receive with every feeding.

◗ Flagyl 500 mg IV every 8h◗ Acetaminophen two tablets every 4h prn




2. Calculate how many tablets of allopurinol will be given PO. Supply: 100 mg/tablet.

3. Calculate how many mL/hr to set the IV pump to infuse Fortaz. Supply: 1-g vial to be diluted with 10 mL of sterile water and further diluted in 50 mL NS to infuse over 30 min.

4. Calculate how many mL of aztreonam to draw from the vial. Supply: 2-g vial tobe diluted with 10 mL of sterile water and further diluted in 100 mL NS to infuse over 60 min.

5. Calculate how many mL/hr to set the IV pump to infuse Flagyl. Supply: 500 mg/100 mL to infuse over 1 hr.


Case Studies 2 4 3

2. Calculate how many mL/hr the child will receive IV.

3. Calculate how many mg of aminophylline the child will receive every 6h. Cal-culate how many mL/hr you will set the IV pump. Supply: 50 mg/10 mL to infuse over 5 min.

4. Calculate how many mg of cefotaxime the child will receive every 12 hr. Calculate how many mL/hr you will set the IV pump. Supply: 40 mg/mL to infuse over 30 min.

5. Calculate how many mg of vancomycin the child will receive every 12 hr. Calculate how many mL/hr you will set the IV pump. Supply: 5 mg/mL to infuse over 1 hr.

CASE STUDY 18 Bronchopulmonary Dysplasia

A neonate born at 24 weeks’ gestation diagnosed with respiratory distress syndromeand respiratory failure is now 28 weeks’ gestation (weight 996 g) with bron-chopulmonary dysplasia. This child remains in the Neonatal Intensive Care Unit(NICU) on oxygen therapy and enteral feedings. The orders from the physicianinclude:

◗ Complete blood count, chemistry panel, ABGs, chest x-ray, CPPD with nebu-lizations, glucose monitoring, caffeine citrate levels, and newborn screen

◗ NG feedings with Special Care with Iron 120 kcal/kg/day◗ Chlorothiazide (Diuril) 10 mg/kg/day PO◗ Fer-In-Sol 2 mg/kg/day◗ Vitamin E 25 units/kg/day in divided doses every 12h◗ Caffeine citrate 5 mg/kg/dose daily



1. Calculate how many total calories the child will receive daily. Calculate howmany mL/day the child will receive. Supply: 24 kcal/oz.

2. Calculate how many mg of chlorothiazide the child will receive daily. Calculatehow many mL/day the child will receive. Supply: 250 mg/5 mL.

3. Calculate how many mg of Fer-In-Sol the child will receive daily. Calculatehow many mL/day the child will receive. Supply: 15 mg/0.6 mL.



CASE STUDY 19 Cerebral Palsy

A 13-year-old child (weight 38 kg) with cerebral palsy being cared for in a children’sfacility is admitted to the hospital for seizure evaluation. The orders from the physi-cian include:

◗ Complete blood count, chemistry panel, urinalysis, dilantin levels, EEG, andCT scan

◗ Vitals every 4h◗ Seizure precautions◗ Lactulose 3 g PO tid◗ Valproic acid (Depakote) 30 mg/kg/day PO in three divided doses◗ Diazepam (Valium) 2.5 mg PO daily◗ Chlorothiazide (Thiazide) 250 mg PO daily◗ Phenytoin (Dilantin) 5 mg/kg/day PO in three divided doses



1. Calculate how many mL of lactulose the child will receive. Supply: 10 g/15 mL.

2. Calculate how many tablets of Depakote the child will receive per dose. Supply: 125 mg/tablet.

3. Calculate how many tablets of diazepam the child will receive per dose. Supply: 5 mg/tablet.

4. Calculate how many tablets of chlorothiazide the child will receive per dose.Supply: 250 mg/tablet.

5. Calculate how many mL of Dilantin the child will receive per dose. Supply:125 mg/5 mL.

4. Calculate how many units/dose of vitamin E the child will receive every 12 hr. Calculate how many mL/dose the child will receive. Supply: 67 units/mL.

5. Calculate how many mg of caffeine citrate the child will receive daily. Calculatehow many mL/dose the child will receive. Supply: 10 mg/mL.


Case Studies 2 4 5

CASE STUDY 20 Hyperbilirubinemia

A 4-day-old neonate born at 35 weeks’ gestation (weight 2210 g) is readmitted tothe hospital for treatment of dehydration and jaundice with a bilirubin level of 21mg/dL. The orders from the physician include:

◗ Phototherapy and exchange transfusion through an umbilical venous catheter◗ Total and indirect bilirubin levels, electrolytes, complete blood count, and

type and crossmatch◗ Continuous cardiorespiratory monitoring◗ Vitals every 2h◗ Monitor intake and output◗ Albumin 5% infusion 1 g/kg 1 hr before exchange◗ Ampicillin 100 mg/kg/dose IV every 12h◗ Gentamicin 4 mg/kg/dose IV every 12h◗ NPO before exchange, then 120 mL/kg/day formula◗ IV D10W 120 mL/kg/day



1. Calculate how many g of albumin the infant will receive before exchangetherapy.

2. Calculate how many mg/dose of ampicillin the infant will receive every 12 hr.Calculate how many mL the infant will receive. Supply: 250 mg/ 5 mL IV pushover 5 min.

3. Calculate how many mg/dose of gentamicin the infant will receive every 12 hr.Calculate how many mL the infant will receive. Supply: 2 mg/mL.

4. Calculate how many mL/day of formula the infant will receive.

5. Calculate how many mL/hr to set the IV pump.

CASE STUDY 21 Spontaneous Abortion

A 31-year-old female is admitted to the hospital to control severe hemorrhage aftera spontaneous abortion. The orders from the physician include:

◗ CBC to determine blood loss◗ WBC with differential to rule out infection◗ Type and crossmatch for 2 units of blood◗ Obtain Coombs’ test to determine Rh status◗ Administer Rhogam 300 mcg IM if patient is Rh-negative with a negative

indirect Coombs’ test



CASE STUDY 22 Bipolar Disorder

A 25-year-old female is brought to the hospital by her friends after she fainted atthe PowerShop. Her friends reported that she has been very sad, withdrawn, andnot involved in any of her usual activities for some time but had suddenly become“full of energy” at the PowerShop. The orders from the physician include:

◗ CBC and electrolytes◗ WBC with differential◗ BUN and creatinine◗ Liver panel◗ Lithium levels◗ IV 0.9% NS at 75 mL/hr◗ Lithium 300 mg PO tid◗ Clonazepam 0.5 mg PO bid; increase to 1 mg PO bid after 3 days◗ Doxepin 50 mg PO tid◗ Intake and output


◗ IV D5/0.9% NS at 100 mL/hr◗ IV oxytocin (Pitocin) 10 Units infused at 20 mU/min◗ Prepare for a dilatation and curettage (D&C)◗ Complete bed rest. Monitor bedpan for contents for intrauterine material◗ Administer meperidine (Demerol) 50 mg IM every 4h for severe

discomfort◗ Administer ibuprofen 400 mg PO every 6h for mild discomfort◗ Monitor vital signs every 4h for 24 hr◗ Monitor urine output◗ Note the amount, color, and odor of vaginal bleeding



1. Calculate how many mL of Rhogam the patient will receive. Supply: Rhogam300 mcg/mL vial. Administer into the deltoid muscle within 72 hr of abortion.


3. Calculate how many mL/hr to set the IV pump to infuse oxytocin 10 units.Supply: Oxytocin 10 units in 500 mL D5/NS.

4. Calculate how many mL of meperidine (Demerol) will be given IM. The pre-filled syringe is labeled 100 mg/mL.

5. Calculate how many tablets of ibuprofen will be given PO. Supply: 200 mg/tablet.


Case Studies 2 4 7



2. Calculate how many capsules of lithium will be given PO. Supply: 150 mg/capsule.

3. Calculate how many tablets of clonazepam will be given PO. Supply: 0.5-mgtablets.

4. Calculate how many tablets of clonazepam will be given PO after 3 days. Supply: 0.5-mg tablets.

5. Calculate how many tablets of doxepin will be given PO. Supply: 25-mg tablets.

CASE STUDY 23 Anorexia Nervosa

A 17-year-old female high school student is admitted by her parents for self-induced starvation, vomiting, and laxative abuse. The 12-week hospital stay is formanagement of diet with a 1- to 2-lb/week weight gain goal. The orders from thephysician include:

◗ DSM-IV evaluation◗ Nutritional consult for 1500-calorie diet advance to 3500 calories over 12 weeks◗ CBC, platelet count, and sedimentation rate◗ WBC with differential◗ Electrolytes, BUN, and creatinine◗ Liver enzymes◗ Urinalysis◗ ECG◗ Daily weight◗ Intake and output◗ 1000 mL IV D5/LR with 20 mEq K+ to infuse over 8 hr◗ Olanzapine (Zyprexa) 10 mg PO HS◗ Fluoxetine (Prozac) 60 mg/day PO every AM

◗ Amitriptyline 25 mg PO qid◗ Cyproheptadine 32 mg/day PO in 4 divided doses



1. Calculate how many mL/hr to set the IV pump.

2. Calculate how many tablets of olanzapine (Zyprexa) will be given at HS. Supply: 5-mg tablets.



CASE STUDY 24 Clinical Depression

A 44-year-old successful businessman with a wife and two children, and diagnosedwith clinical depression, has received several months of treatment with antidepres-sants and psychotherapy. The depression has not responded to therapy. He hasbecome suicidal, and he has agreed to try electroconvulsive therapy (also calledECT). The orders from the physician include:

◗ Admit for ECT◗ CBC and urinalysis◗ ECG◗ NPO after midnight◗ Obtain AM weight◗ Obtain baseline vitals 60 min before procedure◗ Start IV D5/0.45% at 100 mL/hr◗ Administer glycopyrrolate (Robinul) 4.4 mcg/kg IM 30 min preoperatively◗ Zoloft 50 mg PO every AM

◗ Sinequan 25 mg PO tid◗ Parnate 30 mg/day PO in 2 divided doses




2. Calculate how many mL of glycopyrrolate (Robinul) will be given IM. Supply:200 mcg/mL. Patient weight: 175 lb.

3. Calculate how many tablets of sertraline (Zoloft) will be given PO. Supply: 50-mg tablets.

4. Calculate how many capsules of doxepin (Sinequan) will be given PO. Supply:25-mg capsules.

5. Calculate how many tablets of tranylcypromine (Parnate) will be given PO.Supply: 10-mg tablets.

3. Calculate how many mL of fluoxetine (Prozac) will be given PO. Supply: 20 mg/5 mL.

4. Calculate how many tablets of amitriptyline will be given PO. Supply: 10 mg/5 mL.

5. Calculate how many mL of cyproheptadine will be given PO. Supply: 2 mg/5 mL.


Case Studies 2 4 9

CASE STUDY 25 Alzheimer’s Disease

A 62-year-old executive is experiencing difficulty remembering and performingfamiliar tasks, problems with abstract thinking, and changes in mood and behav-ior. He is hospitalized for evaluation. The orders from the physician include:

◗ CT of the brain◗ EEG and cerebral blood flow studies◗ CBC and electrolytes◗ Cerebrospinal fluid analysis◗ Urinalysis◗ 1000 mL IV D5/0.45% NS to infuse over 8 hr◗ Donepezil (Aricept) 5 mg PO HS◗ Thioridazine (Mellaril) 25 mg PO tid◗ Imipramine (Tofranil) 50 mg PO qid◗ Temazepam (Restoril) 7.5 mg PO HS




2. Calculate how many tablets of donepezil (Aricept) will be given PO. Supply: 5-mg tablets.

3. Calculate how many tablets of thioridazine (Mellaril) will be given PO. Supply:25-mg tablets.

4. Calculate how many tablets of imipramine (Tofranil) will be given PO. Supply:25-mg tablets.

5. Calculate how many tablets of temazepam (Restoril) will be given PO. Supply:15-mg tablets.

CASE STUDY 26 Otitis Media

An 18-month-old child is seen in the nurse practitioner’s office for reoccurring oti-tis media and fever. The child’s weight is 23 lb. The orders from the nurse practi-tioner include:

◗ Amoxicillin 45 mg/kg/day PO in divided doses every 12h◗ Acetaminophen (Tylenol) 120 mg PO every 4h alternating with Ibuprofen

5 mg/kg PO every 6h if temperature is 102.5° F or below and 10 mg/kg iftemperature is greater than 102.5° F

◗ Cetirizine (Zyrtec) 2.5 mg PO every 12h



CASE STUDY 27 Seizures

An 8-year-old child is admitted to the pediatric hospital with seizures secondary toa head injury following a fall on the playground. The child’s weight is 60 lb. Theorders from the physician include:

◗ Admit to pediatric intensive care◗ Bedrest in quiet, darken environment◗ Complete blood count, chemistry panel, urinalysis, EEG, skull and neck

x-ray and CT scan◗ Vitals every 2h◗ Monitor intake and output◗ Seizure precautions◗ IV D5W/0.45% NS at 500 mL/8 hr◗ Phenytoin (Dilantin) 2 mg/kg/min IV◗ Diazapam (Valium) 0.3 mg/kg IV push given over 3 minutes every 15–30 min

to a total dose of 10 mg, repeat every 2–4 hr for seizure activity followingDilantin administration

◗ Acetaminophen (Tylenol) 320 mg PO every 4 hours alternating with Ibuprofen7.5 mg/kg PO every 6 hours



1. Calculate how many mL/hr to set the IV pump. Supply: D5W/0.45% NS 500 mL.

◗ Pedialyte 75 mL per kg PO not to exceed more than 100 mL in any 20-minuteperiod during the first 8 hr



1. Calculate how many mL/dose of amoxicillin will be given PO. Supply: amoxi-cillin 125 mg/5 mL solution.

2. Calculate how many mL of acetaminophen (Tylenol) will be given PO for atemperature of 102°. Supply: acetaminophen 100 mg/mL solution.

3. Calculate how many mL of ibuprofen will be given PO for a temperature of102°. Supply: ibuprofen 100 mg/5 mL solution.

4. Calculate how many mL of Zyrtec will be given PO. Supply: Zyrtec 1 mg/mL.

5. Calculate how many mL/hr/8 hr of Pedialyte the patient will receive PO duringthe first 8 h.


Case Studies 2 5 1

2. Calculate how many mL/hr to set the IV pump to administer Dilantin. Supply: dilantin 100 mg/50 mL to be administered over 15 minutes.

3. Calculate how many mL of diazepam will be given IV push over 3 minutes.Supply: diazepam 5 mg/mL.

4. Calculate how many mL of acetaminophen will be given every 4 hours PO.Supply: acetaminophen 100 mg/mL.

5. Calculate how many mL of ibuprofen will be given PO every 6 hours. Supply: ibuprofen 100 mg/5 mL.

CASE STUDY 28 Fever of Unknown Origin

A 10-year old child is admitted to the pediatric hospital with fever of unknown ori-gin. The child’s weight is 80 lb. The orders from the physician include:

◗ Admit to the Pediatric Unit◗ Complete blood count with differential, chest x-ray, urinalysis, chemistry

panel, and sputum culture◗ Vitals every 4 hours◗ Monitor intake and output◗ Acetaminophen (Tylenol) 400 mg PO every 4h alternating with

ibuprofen 7.5 mg/kg PO every 6h◗ IV D5W/0.45% NS at 500 mL/4 hr◗ Unasyn 1500 mg IV every 6h



1. Calculate how many mL of acetaminophen will be given every 4 hours PO. Supply: acetaminophen 500 mg/15 mL.

2. Calculate how many mL of ibuprofen will be given every 6h PO. Supply: ibuprofen 100 mg/5 mL.

3. Calculate how many mL/hr to set the IV pump. Supply: D5W/0.45% NS 500 mL.

4. Calculate the gtt/min using a microtubing (60 gtt/mL).

5. Calculate how many mL/hr to set the IV pump to administer Unasyn. Supply: Unasyn 1.5 g/50 mL over 30 minutes.



CASE STUDY 29 TURP with CBI

A 58-year-old male is admitted to the medical/surgical unit following surgery fortransurethral resection of prostate. The physician’s post-operative orders include:

◗ Admit to the medical/surgical unit◗ Monitor intake and output◗ Monitor urinary output hourly◗ Vitals every 2 hr◗ Monitor for symptoms of TURP Syndrome◗ Adjust rate of continuous bladder irrigation 3 Liter bags of sterile normal

saline to maintain a patent catheter, adjust rate to maintain pink to clearurine, and maintain urinary catheter traction

◗ IV D5W/0.45% normal saline 1000 mL/8 hr◗ Ciprofloxacin (Cipro) 400 mg IV every 12 hr◗ Docusate sodium (Colace) 100 mg PO bid◗ Dimenhydrinate 25 mg IV every 4 hr prn◗ Acetaminophen (Tylenol) 300 mg with 30 mg of codeine PO 1 to

2 tablets every 4 to 6 hr prn◗ Discontinue IV when drinking well◗ Complete blood count, electrolytes, creatinine in am



1. Calculate how many mL/hr to set the IV pump. Supply: D5W/0.45% NS 1000 mLbag.

2. Calculate how many gtt/min using 20 gtt/mL IV tubing.

3. Calculate how many mL/hr to set the IV pump to deliver the Cipro. Supply: Ciprofloxasin 400 mg/200 mL D5W to infuse over 60 minutes.

4. Calculate how many capsules to give of Colace. Supply: docusate sodium 100 mg/capsule.

5. Calculate how many mL will be given of dimenhydrinate.

CASE STUDY 30 Hypercholesterolemia

A 40-year-old male returns to his nurse practitioner’s office after 3 months for a cho-lesterol level of 240 mg/dl. The nurse practitioner’s orders include:

◗ Continue low-fat, high fiber diet◗ Continue to briskly walk 3 to 4 times weekly for 30 minutes◗ Stop smoking and begin Chantix 0.5 mg PO once daily for days 1–3 then

0.5 mg PO bid for Day 4–7, then 1 mg PO for day 8◗ Atorvastatin (Lipitor) 20 mg PO daily◗ Cholestyramine resin 4 g/dose PO bid to be taken 1 hr before Lipitor


Case Studies 2 5 3

◗ Niacin 1.5 g/day PO◗ Return appointment in 4 weeks for lipid levels.



1. Calculate how many tablets of Chantix the patient will be taking on days 1–3.Supply: Chantix 0.5 mg tablets.

2. Calculate how many tablets of Chantix the patient will be taking on day 8.Supply: Chantix 0.5 mg tablets.

3. Calculate how many tablets of Lipitor the patient will be taking. Supply: Lipitor 10 mg tablets.

4. Calculate how many g/day of cholestyramine resin the patient will be taking.Supply: Cholestyramine resin 4 g/dose powder to be mixed with 4 to 6 oz offluid.

5. Calculate how many tablets/day of niacin the patient is taking. Supply: Niacin500 mg tablets.

CASE STUDY 31 Hypertension

A 60-year-old male returns to his nurse practitioner’s office after 3 months for ele-vated blood pressure. Patient’s weight: 90 kg. The nurse practitioner’s ordersinclude:

◗ Continue on low-sodium diet◗ Continue to briskly walk 3 to 4 times weekly for 30 minutes◗ Maintain a fluid intake of 2 L/day◗ Nifedipine (Procardia XL) 60 mg PO once daily for 14 days then return to the

office for re-evaluation◗ Docusate sodium (Colace) 100 mg PO bid◗ Hydrochlorothiazide (HydroDIURIL) 25 mg daily PO in am with a glass of

orange juice◗ Report any weight gain of greater than 2 lb/day◗ Return appointment in 14 days for re-evaluation of blood pressure



1. Calculate how many mL/meal the patient will need to consume.



2. Calculate how many tablets of nifedipine the patient is taking. Supply: ProcardiaXL 30 mg/tablets.

3. Calculate how many capsules of docusate sodium the patient is taking. Supply:Colace 100 mg/capsule.

4. Calculate how many tablets of hydrochlorothiazide the patient is taking. Supply:HydroDIURIL 50 mg/tablets.

5. Calculate the weight gain from 90 kg to 95 kg that will be reported to the nursepractitioner in lb.

CASE STUDY 32 Diabetic Ketoacidosis

A 16-year-old is admitted to the medical intensive care unit with diabetic ketoaci-dosis secondary to fever. The patient weighs 125 lbs. The orders from the physicianinclude:

◗ Admit to the medical intensive care unit◗ Complete blood count, electrolytes, blood sugar, ABGs, and ECG◗ Blood, urine, and sputum cultures◗ Electrolytes and blood sugars hourly until stable◗ Strict intake and output◗ Daily weight◗ Vitals hourly × 4 then every 2 hours × 4 then every 4 hr◗ IV 0.9% NS 1000 mL/8 hr◗ Regular insulin 0.15 units/kg IV bolus followed by the continuous intra-

venous infusion of regular insulin 0.1 unit/kg/hr in 0.9% NS◗ Change IV fluids to D5W/0.45% NS when plasma glucose falls to under

250 mg/dL at 10 mL/kg/hr◗ Ampicillin sodium 500 mg every 6 hr IVPB for 3 days



1. Calculate the mL/hr to set the IV pump to 1000 mL/8 hr. Supply: 0.9% NS 1000 mL.

2. Calculate the mL for the IV bolus to infuse regular insulin at 0.15 units/kg.Supply: 250 mL 0.9% NS with 250 units regular insulin.

3. Calculate the mL/hr to set the IV pump for the continuous infusion of regular insulin at 0.1 unit/kg/hr in 0.9% NS. Supply: 250 mL 0.9% NS with250 units regular insulin.


Case Studies 2 5 5

4. Calculate the mL/hr to set the IV pump after the plasma glucose falls to under250 mg/dL. Supply: D5W/0.45% NS 1000 mL

5. Calculate the mL/hr to set the IV pump to infuse ampicillin sodium. Supply: ampicillin sodium 1 g/100 mL over 30 min.

CASE STUDY 33 End-Stage Renal Failure

A 60-year-old patient is seen at the dialysis center for weekly dialysis treatment. Thepatient weighs 140 lbs after dialysis. The orders from the physician include:

◗ Obtain weight three times weekly prior to and after dialysis treatment◗ Furosemide 120 mg PO bid◗ Metolazone (Zaroxolyn) 10 mg PO daily◗ Enalapril maleate (Vasotec) 2.5 mg PO bid◗ Epogen 100 units/kg IV three times weekly in venous line following dialysis◗ Calcium Carbonate 10 g/day in divided doses with meals



1. Calculate how many tablets of Furosemide the patient is taking. Supply:Furosemide 80 mg/tablets.

2. Calculate how many tablets of Zaroxolyn the patient is taking. Supply: Metola-zone 5 mg/tablet.

3. Calculate how many tablets of Vasotec the patient is taking. Supply: Enalaprilmaleate 2.5 mg/tablets.

4. Calculate how many mL of Epogen the patient should receive three timesweekly. Supply: Epogen 4,000 units/mL.

5. Calculate how many tablets/meal of calcium carbonate the patient will receive.Supply: calcium carbonate 1500 mg/tablets.



CASE STUDY 34 Fluid Volume Deficit

A five-year old child is admitted to the pediatric unit for fluid volume deficit sec-ondary to gastroenteritis. The child’s weight is 35 lb. The orders from the physicianinclude:

◗ Admit to pediatric unit for 24-hour observation◗ Monitor intake and output◗ IV 50 mL/kg 0.9% NS/2.5% dextrose over 4 hr◗ Discontinue IV when taking PO fluids without emesis◗ Acetaminophen (Tylenol) 400 mg/dose PO every 4 hours alternating with

ibuprofen 7.5 mg/kg PO every 6 hours◗ Encourage sips of fluids every 10 minutes if not vomiting, repeated every 15

minutes until able to consume 30 mL then fluids as tolerated at 1.5 oz/lb/24 hr◗ Pedialyte 53 oz/24 hr when tolerating fluids



1. Calculate the mL/hr to set the IV pump to infuse 50 mL/kg/4 hr. Supply: 1000 mL 0.9% NS/2.5% dextrose.

2. Calculate how many mL of acetaminophen will be given PO. Supply: acetaminophen 100 mg/mL solution.

3. Calculate how many mL of ibuprofen per dose will be given PO. Supply:ibuprofen 100 mg/5 mL solution.

4. Calculate how many mL/hr of fluids the child will receive.

5. Calculate how many mL/hr of pedialyte the child will receive.

CASE STUDY 35 Increased Intracranial Pressure

A 35-year-old male is admitted to the hospital with signs and symptoms ofincreased intracranial pressure secondary to brain metastasis. The patient weighs75 kg. The orders from the physician include:

◗ Admit to oncology unit◗ IV 0.9% NS 1000 mL/10 hr◗ Loading dose of phenytoin (Dilantin) 10 mg/kg IV push (50 mg/min) then

Dilantin 100 mg IV every 8 hr◗ Mannitol 0.5 g/kg/10 min IV initial dose followed by Mannitol 0.25 g/kg IV

every 4 hr◗ Dexamethasone 10 mg IV◗ Furosemide 0.5 mg/kg IV push


Case Studies 2 5 7

◗ Elevate HOB 25–30 degrees to promote intracranial drainage◗ Bedrest in a quiet, darkened environment



1. Calculate the mL/hr to set the IV pump to infuse 0.9% NS. Supply: 1000 mL0.9% NS.

2. Calculate how many mL of Dilantin the patient will receive as a loading dose.Supply: Dilantin 1000 mg/20 mL 0.9% NS.

3. Calculate the mL/hr to set the IV pump to infuse the Mannitol ordered every 4 h. Supply: Mannitol 100 g/500 mL D5W.

4. Calculate how many mL of dexamethasone will be given IV push. Supply:Decadron 120 mg/5 mL.

5. Calculate how many mL of furosemide will be given IV push. Supply:furosemide 10 mg/mL.

CASE STUDY 36 Breast Cancer

A patient is admitted to the hospital with nausea, shortness of breath, and fatigue10 days after receiving chemotherapy for breast cancer. The orders from the physi-cian include:

◗ Admit to Oncology Unit◗ O2 at 2 L/min per nasal cannula◗ Complete blood cell count (CBC) with differential, chest x-ray, urinalysis,

chemistry panel, and sputum culture◗ Vitals every 4 hours (call if temperature above 102�F)◗ Bedrest with BRP◗ Monitor intake/output◗ Type and cross-match for 1 unit of PRBC for Hg 8 g/dL or below ◗ Filgrastim (Neupogen) 5 mcg/kg/day IV until the ANC reaches 10,000/mm3

◗ 6 pack of platelets if count under 20,000◗ Premedicate prior to blood transfusion with acetaminophen (Tylenol) 650 mg

PO and diphenhydramine (Benadryl) 25 mg IV◗ Metoclopramide (Reglan) 2 mg/kg IV every 2 hours for two doses◗ IV D5W at 100 mL/hr






CASE STUDY 37 Severe Abdominal Pain

A 12-year-old patient is admitted to the hospital with severe abdominal pain in theright lower quadrant. The orders from the physician include:

◗ Admit to Pediatric Unit◗ Weight 88 lb◗ Vitals every 2 hours until stable, then every 4 hours◗ Ultrasound for possible ruptured appendix◗ CBC with differential◗ IV D5W/0.45% NS @ 1000 mL/8 hr◗ Clindamycin (Cleocin) 300 mg IV every 6 hours◗ Cefotaxime (Claforan) 50 mg/kg IV every 12 hours◗ Morphine sulfate 3 mg IV push every 3 to 4 hours prn for severe pain



1. Calculate the weight of the patient in kilograms.


3. Calculate mL/hr to set the IV pump to infuse clindamycin 300 mg. Supply:Cleocin 300 mg/50 mL NS to infuse over 20 minutes.

2. Calculate how many mL per day of filgrastim (Neupogen) will be given for apatient weighing 150 lb. Supply: Neupogen 300 mcg/mL.

3. Calculate how many mg of metoclopramide (Reglan) the patient will receive IV.Patient weighs 150 lb. Supply: Metoclopramide 5 mg/mL.

4. Calculate mL/hr to set the IV pump to infuse 1 unit of PRBC over 3 hours. Sup-ply: PRBC 1 unit = 450 mL

*Preventing Medication Errors: Before administration of the PRBC, the nursemust change the IV to 0.9% NS and strictly follow the protocol for administra-tion of blood or blood components. Use of other IV solutions will damage theblood components: D5W solutions will cause red blood cells to aggregate andlyse and Lactated Ringers will cause blood to clot.

5. Calculate how many mL of diphenhydramine (Benadryl) the patient will receivefrom a vial labeled diphenhydramine 50 mg/mL to be administrated over 1 minute IV push.


Case Studies 2 5 9

CASE STUDY 38 Acute Asthma Attack

A patient is admitted to the hospital during an acute asthma attack. The orders fromthe physician include:

◗ Admit to the Pulmonary Unit◗ O2 at 2 L/min per nasal cannula ◗ Vitals every 2 hours until stable, then every 4 hours◗ CBC with differential, chemistry panel, and blood gases◗ Bedrest in high Fowler’s position◗ IV D5W/1/2 NS at 1000 mL/10 hr◗ Levalbuterol (Xopenex) 1.25 mg administered every 4 hours via nebulizer for

wheezing (1.25 vials)◗ Fluticasone and salmeterol (Advair) 250/50 inhaler every 12 hours◗ Weight 176 lb◗ Methylprednisolone (Solu-Medrol) 80 mg infused IV push over 3 minutes

every 6 hours◗ Azithromycin (Zithromax) 500 mg PO on day 1 followed by 250 mg PO daily

on days 2 to 5 for a total dose of 1.5 g ◗ Cimetidine (Tagamet) 300 mg IV every 6 hours





3. Calculate how many mL of Solu-Medrol the patient will receive IV push froman Act-O-Vial System labeled 125 mg/2 mL.

4. Calculate how many tablets of azithromycin will the patient receive from a unitdose of 250 mg/capsular for the initial dose of 500 mg.

5. Calculate mL/hr to set the IV pump to infuse cimetidine 300 mg IV. Supply:Tagamet 300 mg/50 mL of D5W and infused over 20 minutes.

4. Supply: Claforan 2-g vial to be reconstituted with 10 mL sterile water and furtherdiluted in 50 mL NS to infuse over 30 minutes. Calculate mL to draw from the vialto mix with 50 mL NS and calculate mL/hr to set the IV pump to infuse cefotaxime.

5. Calculate the mL of morphine sulfate to be given IV push. Supply: Morphine sul-fate 4 mg/mL to be further diluted in 5 mL sterile water or NS and administeredover 4 to 5 minutes.



CASE STUDY 39 Right Total Hip Replacement

A patient is admitted to the hospital for a right total hip replacement. The ordersfrom the physician include:

◗ Admit to Orthopedic Unit◗ IV D5W/NS at 100 mL/hr◗ CBC with differential, chemistry panel, BUN, creatinine, and urinalysis◗ Monitor intake/output◗ Atenolol 50 mg PO daily◗ Lisinopril 5 mg PO daily◗ Enoxaparin (Lovenox) 40 mg SQ every 12 hours◗ Dimenhydrinate 50 mg IV every 4 hours for nausea and vomiting ◗ Morphine 10 mg IV every 4 hours prn for pain



1. Calculate how many tablets of atenolol will the patient receive from a unit doseof 25 mg/tablet.

2. Calculate how many tablets of lisinopril will the patient receive from a unitdose of 2.5 mg/tablet.

3. Calculate how many mL of Lovenox the patient will receive SQ from a viallabeled enoxaparin 80 mg/0.8 mL.

4. Calculate the mL of dimenhydrinate to be given IV. Supply: Dimenhydrinate50 mg/mL to be further diluted in 10 mL NS and administered slowly over2 minutes.

5. Calculate the mL of morphine sulfate to be given IV. Supply: Morphine sulfate8 mg/mL to be further diluted in 5 mL sterile water or NS and administeredover 4 to 5 minutes.

CASE STUDY 40 Colon Resection

A patient is admitted to the hospital for a colon resection. The orders from thephysician include:

◗ Admit to Medical/Surgical Unit◗ IV NS with KCl 20 mEq/L 1000 mL/12 hr◗ CBC, electrolytes, urea, glucose, creatinine◗ Enoxaparin (Lovenox) 40 mg SQ daily◗ Cefoxitin 1 g IV every 8 hours


Case Studies 2 6 1

◗ Ranitidine 50 mg IV every 8 hours◗ Tamsulosin (Flomax) 0.8 mg PO daily PC ◗ Calcium carbonate (Os-Cal) 1.25 g PO daily (1250 mg/tablet)




2. Calculate mL/hr to set the IV pump to infuse cefoxitin (Mefoxin) 1 g IV. Supply: Cefoxitin 1 g in 50 mL 0.9% NS to infuse over 30 minutes.

3. Calculate mL/hr to set the IV pump to infuse ranitidine 50 mg IV. Supply: Ranitidine (Zantac) 50 mg/100 mL D5W to be administered over 20 minutes.

4. Calculate how many capsules of Flomax the patient will receive from a unitdose of 0.4 mg/capsule.

5. Calculate how many tablets of Os-Cal the patient will receive from a unit doseof 1250 mg/tablet.

CASE STUDY 41 Left Total Knee Replacement

A patient is admitted to the hospital for a left total knee replacement. The ordersfrom the physician include:

◗ Admit to Orthopedic Unit◗ IV D5/LR with 20 mEq KCl 1000 mL every 8 hours◗ CBC with differential, chemistry panel, and blood gases◗ Cefazolin 1 g IV 1 hour prior to surgery and 500 mg every 8 hours post-

operation◗ Enoxaparin (Lovenox) 30 mg SQ daily◗ Ferrous sulfate 0.3 g PO daily◗ Docusate sodium 100 mg PO bid




2. Calculate mL/hr to set the IV pump to infuse cefazolin 1 g IV. Supply: Cefazolin(Ancef) 1 g/100 mL D5W to be administered over 30 minutes.



CASE STUDY 42 Chest Pain

A patient is admitted to the hospital for chest pain. The orders from the physicianinclude:

◗ Admit to intensive care unit (ICU)◗ IV nitroglycerin 10 mcg/min and increase infusion rate by 10 mcg/min every

10 minutes until relief of pain (NTG 50 mg/250 mL D5W)◗ CK/CKMB and Troponin I at 6 and 10 hours◗ CBC, electrolytes, urea, creatinine, and ABGs◗ O2 per nasal cannula◗ Accurate intake/output◗ Chest x-ray◗ ECG at 6 and 10 hours◗ Vitals every 2 hours until stable and then every 4 hours◗ ASA 160 mg PO � 1 (80 mg tablet)◗ Morphine 2.5 mg IV administered every 5 minutes until pain subsides (up to

a maximum of 20 mg can be given)



1. Calculate mL/hr to set the IV pump to infuse nitroglycerin 10 mcg/min. Sup-ply: Nitroglycerin 50 mg/250 mL D5W.

2. The patient is now receiving 15 mL/hr of nitroglycerin. How many mcg/min isthe patient receiving?

3. Calculate how many tablets of ASA the patient will receive from a unit dose of80 mg/tablet.

4. Calculate how many mL of morphine the patient will receive IV from a viallabeled morphine 5 mg/mL. Mix with 5 mL sterile water for injection andadminister over 5 minutes.

3. Calculate mL/hr to set the IV pump to infuse cefazolin 500 mg IV. Supply:Cefazolin (Ancef) 500 mg/50 mL D5W to be administered over 30 minutes.

4. Calculate how many mL of Lovenox the patient will receive SQ from a viallabeled enoxaparin 40 mg/0.4 mL.

5. Calculate how many tablets of ferrous sulfate the patient will receive from aunit dose of 300 mg/tablet.


Case Studies 2 6 3

CASE STUDY 43 Pneumococcal Meningitis

A child with pneumococcal meningitis is admitted to the hospital. The orders fromthe physician include:

◗ Admit to the Pediatric ICU◗ CBC, electrolytes, urea, creatinine, liver enzymes, bilirubin, and urinalysis◗ Vital signs every 2 hours until stable, then every 4 hours◗ Daily weight (44 lb when admitted)◗ Accurate intake/output◗ IV 0.9% normal saline bolus 10 mL/kg followed by D5W/0.45% NS at

50 mL/hr◗ Acetaminophen 15 mg/kg/dose PO every 4 hours prn for fever or mild pain◗ Ceftriaxone (Rocephin) 50 mg/kg/dose IV every 12 hours three times, then

every 24 hours◗ Vancomycin 60 mg/kg/day IV divided in four equal doses every 6 hours



1. Calculate the weight of the child in kilograms.

2. Calculate how many mL the child will receive IV bolus.

3. Calculate how many mL/dose of acetaminophen the child will receive from astock bottle of elixir labeled acetaminophen 80 mg/2.5 mL.

4. Calculate how many mg/dose of ceftriaxone the child will receive and then calculate mL/hr to set the IV pump to infuse ceftriaxone. Supply: Premixed IVRocephin 1 g/50 mL to be administered over 30 minutes.

5. Calculate how many mg/dose of vancomycin the child will receive and thencalculate mL/hr to set the IV pump to infuse vancomycin. Supply: Premixed IVvancomycin 500 mg/100 mL to be administered over 30 minutes.

5. The patient is still reporting pain at 8 on a scale of 1 to 10 and a third dose ofmorphine is to be given. Calculate how many mL of morphine the patient hasnow received with three doses.



CASE STUDY 44 Diabetic Ketoacidosis

A child is admitted to the hospital in diabetic ketoacidosis with dehydration andvomiting. The orders from the physician include:

◗ Admit to Pediatric ICU◗ Blood sugar, electrolytes, urea, creatinine, CBC, HgA1C, and urinalysis◗ Vitals every 1 hour◗ NPO◗ Accurate intake/output◗ Hourly blood glucose◗ Weigh daily (54 lb when admitted)◗ NS IV bolus 10 mL/kg◗ NS IV 3.5 mL/kg/hr with KCl 20 mEq/L◗ 25 units regular insulin/250 mL NS at 0.1 units/kg/hr◗ Ondansetron (Zofran) IV push 0.1 mg/kg over 2 minutes



1. Calculate the weight of the child in kilograms.

2. Calculate how many mL the child will receive IV bolus.

3. Calculate mL/hr to set the IV pump to infuse the IV NS with KCl 20 mEq/L.

4. Calculate mL/hr to set the IV pump to infuse regular insulin 0.1 units/kg/hr.Supply: Regular insulin 25 units/250 mL NS.

5. Calculate how many mL of ondansetron 0.1mg/kg will be given IV push over 2minutes. Supply: Zofran 2 mg/mL.

CASE STUDY 45 C-Section Delivery

A HIV� patient is admitted to the hospital for C-section delivery. The orders fromthe physician include:

◗ Admit to OB in private room◗ NPO◗ Up ad lib ◗ CBC and electrolytes◗ Type and cross-match for 2 units of blood◗ Admission weight 164 lb◗ Lactated Ringers IV at 100 mL/hr◗ Zidovudine 2 mg/kg IV over 1 hour on admission to labor and delivery then

zidovudine 1 mg/kg/hr continuous IV infusion beginning 3 hours prior to C-section


Case Studies 2 6 5

◗ Cefazolin 1 g IVPB � 1 dose 1 hour prior to C-section◗ Metoclopramide (Reglan) 10 mg IV push every 6 hours prn for nausea and

vomiting◗ Hydrocodone 5 mg and acetaminophen 325 mg PO two tablets every 4 hours

prn for moderate to severe pain◗ Docusate sodium 100 mg PO two capsules bid




2. Calculate how many mL/hr to set the IV pump to infuse zidovudine 2 mg/kgover 1 hour. Supply: Zidovudine 200 mg/50 mL D5W.

3. Calculate mL/hr to set the IV pump to infuse zidovudine 1 mg/kg/hr. Supply:Zidovudine 400 mg/100 mL D5W.

4. Calculate mL/hr to set the IV pump to infuse cefazolin 1 g IV. Supply: Cefazolin(Ancef) 1000 mg/100 mL D5W to be administered over 30 minutes.

5. Calculate how many mL of metoclopramide 10 mg will be given IV push over2 minutes. Supply: Reglan 5 mg/mL.

References

WebMD.com http://www.webmd.com/Merck Manual online http://www.merck.com/mmpe/index.htmlGlobalRPh.com http://www.globalrph.com/PDR for Nurse’s Drug Handbook (2007 edition).


http://www.webmd.com/

http://www.merck.com/mmpe/index.html

http://www.globalrph.com/

ANSWER KEY FOR SECTION 3:CASE STUDIES

Case Study 1 Congestive Heart Failure

Orders requiring calculations: IV of D5W/ 1–2 NS at 50 mL/hr; weight gain; furosemide 40 mg IV every d;digoxin 0.125 mg PO qd; KCl 20 mEq PO tid

1

2

3

4

5

Case Study 2 COPD/Emphysema

Orders requiring calculations: IV of D5W/ 1–2 NS 1000 mL/8 hr; aminophylline IV loading dose of 5.6 mg/kg over 30 min followed by 0.5 mg/kg/hr con-tinuous IV; erythromycin 800 mg IV every 6h; accurateintake/output.

1

2

3

4

5

Case Study 3 Small Cell Lung Cancer

Orders requiring calculations: IV D5W/ 1–2 NS 1000 mL with 10 mEq KCl at 125 mL/hr; Neupogen5 mcg/kg SQ daily; gentamicin 80 mg IV every 8h;Decadron 8 mg IV daily; Fortaz 1 g IV every 8h

1

2

3

4

5

Case Studies 2 6 7

5.6 mg 100 mL 1 kg 140 lb 60 min 5.6 × 14 × 6

kg/30 min 100 mg 2.2 lb 1 hr 3 × 2.2

10 lb 1 kg 10 × 1 10�4.5 kg

2.2 lb 2.2 2.2

50 mL 60 gtt 1 hr 50 × 1 �

50 gtt

hr mL 60 min min

40 mg mL 4� 4 mL

10 mg 1

0.125 mg tablet 0.125� 0.5 tablet

0.25 mg 0.25

20 mEq tablet 2� 2 tablets

10 mEq 1

1000 mL 1000�

125 mL

8 hr 8 hr

470.4�

71.3 mLor

71 mL

6.6 hr hr 50 mL 60 min 50 × 6 300�

100 mL

30 min 1 hr 3 × 1 3 hr

125 mL 20 gtt 1 hr 125 × 2 × 1 250�

41.6 or 42 gtt

hr mL 60 min 6 6 min

3 L day 1000 mL 1000�

1000 mL

day 3 shifts 1 L 1 shift

5 mcg 1 kg 160 lb 5 × 1 × 160 800�363.6 mcg or 364 mcg

kg 2.2 lb 2.2 2.2

80 mg mL 8� 2 mL

40 mg 4

102 mL�

102 mL

1 hr hr

8 mg mL 8� 2 mL

4 mg 4

800 mg 20 mL 1 g 8 × 2� 16 mL

1 g 1000 mg 1

266 mL�

266 mL

1 hr hr

0.5 mg 250 mL 1 g 1 kg 140 lb 0.5 × 25 × 1 × 14

kg/ hr 1 g 1000 mg 2.2 lb 10 × 2.2

175�

7.9 mLor

8 mL

22 hr hr


80 mL 20 mEq 1 L 8 × 2 16�

1.6 mEq

hr 1 L 1000 mL 10 10 hr

Case Study 4 Acquired Immunodefi-

ciency Syndrome (AIDS)

Orders requiring calculations: IV D5W/1–2 NS at 150 mL/hr; acyclovir 350 mg IV every 8h; Neupo gen300 mcg SQ daily; Epogen 100 units/kg SQ three timesa week; vancomycin 800 mg IV every 6h

1

2

3

4

5

Case Study 5 Sickle Cell Anemia

Orders requiring calculations: IV D5W/ 1–2 NS at 150 mL/hr; Zofran 8 mg IV every 8h; morphine sul-fate 5 mg IV prn; Hydrea 10 mg/kg/day PO; folic acid0.5 mg daily PO

1

2

3

4

5

Case Study 6 Deep Vein Thrombosis

Orders requiring calculations: IV D5W/ 1–2 NS with 20 mEq KCl at 50 mL/hr; heparin 5000 units IV pushfollowed by continuous IV infusion of 1000 units/hr;Lasix 20 mg IV bid; morphine 5 mg IV every 4h

1

2

3

4

5

Case Study 7 Bone Marrow Transplant

Orders requiring calculations: IV D5W/ 1–2 NS with 20 mEq KCl/L at 80 mL/hr; Fortaz 2 g IV every 8h;vancomycin 1 g IV every 6h; Claforan 1 g IV every12h; eryth romycin 800 mg IV every 6h

1


150 mL 20 gtt 1 hr 150 × 2 × 1 300�

50 gtt


350 mg 10 mL 35 × 1 35� 7 mL

500 mg 5 5

107 mL 107�

107 mL

1 hr 1 hr

300 mcg 1 mL� 1 mL

300 mcg

100 units mL 1 kg 100 lb 10 × 1 × 1 10� 1.1 mL or 1 mL

kg 4000 units 2.2 lb 4 × 2.2 8.8

800 mg 10 mL 1 g 80 × 1 80� 8 mL

1 g 1000 mg 10 10

108 mL 60 min 108�

108 mL

60 min 1 hr 1 hr

150 mL 10 gtt 1 hr 150 × 1 × 1 150�

25 gtt


50 mL 60 min 50 × 60 3000�

200 mL

15 min 1 hr 15 × 1 15 hr

10 mg 1 kg 125 lb 10 × 1 × 125 1250�

568 mg

kg/ day 2.2 lb 2.2 2.2 day

5 mg mL 5� 0.5 mL

10 mg 10


1 mg 1

50 mL 60 gtt 1 hr 50 × 1 50�

50 gtt

hr mL 60 min min

5000 units mL 5 � 0.5 mL

10,000 units 10

1000 units 250 mL 10 �

10 mL

hr 25,000 units hr

20 mg mL 2� 2 mL

10 mg 1

5 mg mL 5� 0.5 mL

10 mg 10


2

3.

4

5

Case Study 8 Pneumonia

Orders requiring calculations: Clindamycin 400 mg IVevery 6h; guaifenesin 200 mg PO every 4h; ter butaline2.5 mg PO tid; MS Contin 30 mg PO every 4h prn

1

2

3

4

5

Case Study 9 Pain

Orders requiring calculations: IV D5W/ 1–2 NS with 20 mEq KCl/L at 60 mL/hr; IV 500 mL NS with 25 mg dilaudid and 50 mg thorazine at 21 mL/hr;Bumex 2 mg IV every AM after albumin infusion

1

2

3

4

5

Case Study 10 Cirrhosis

Orders requiring calculations: IV D5W/1–2 NS with 20 mEq KCl at 125 mL/hr; IV Zantac 150 mg/250 mLNS at 11 mL/hr; vitamin K 10 mg SQ every AM; Spiro -nolactone 50 mg PO bid; Lasix 80 mg IV every AM

1

Case Studies 2 6 9

2 g 10 mL 10� 10 mL

2 g

60 mL 60 min 60 × 6 360�

120 mL

30 min 1 hr 3 × 1 3 hr

1 g 10 mL 1000 mg 10 × 10 100� 20 mL

500 mg 1 g 5 5

120 mL 60 min 120�

120 mL

60 min 1 hr 1 hr

1 g 4 mL 1000 mg 4 × 10 40� 6.7 mL or 7 mL

600 mg 1 g 6 6

107 mL 107�

107 mL

1 hr 1 hr

800 mg 20 mL 1 g 8 × 2 16� 16 mL

1 g 1000 mg 1 1

266 mL 60 min 266�

266 mL

60 min 1 hr 1 hr

400 mg 4 mL 4 × 4 16� 2.7 mL or 3 mL

600 mg 6 6

53 mL 53�

53 mL

hr hr

53 mL 20 gtt 1 hr 53 × 2 × 1 106�

18 gtt


200 mg tsp 5 mL 20 × 5 100� 33 mL

30 mg 1 tsp 3 × 1 3


5 mg 5

30 mg tablet 30�1 tablet

30 mg 30

60 mL 20 mEq 1 L 6 × 2 12�

1.2 mEq

hr 1 L 1000 mL 10 10 hr

21 mL 25 mg 21 × 25 525�

1.05 mg

hr 500 mL 500 500 hr

21 mL 50 mg 21 × 5 105�

2.1 mg

hr 500 mL 50 50 hr

11 mL 25,000 units 11 × 2500 27,500�

1100 units

hr 250 mL 25 25 hr

2 mg mL 2� 8 mL

0.25 mg 0.25

125 mL 20 gtt 1 hr 125 × 2 × 1 250=

41.66 or 42 gtt



Case Study 12 Preeclampsia

Orders requiring calculations: Methyldopa (Aldo met)250 mg; Hydralazine (Apresoline) 5 mg IV; magnesiumsulfate 4 g in 250 mL D5W loading dose to infuse over30 min; magnesium sulfate 40 g in 1000 mL LR to infuseat 1 g/hr; nifedipine (Procardia) 10 mg sublingual

1

2

3

4

5

Case Study 13 Premature Labor

Orders requiring calculations: Magnesium sulfate at 2 g/hr; terbutaline (Brethine) 0.25 mg SQ; nifedi pine(Procardia) 20 mg; betamethasone 12 mg IM; LR 1000mL over 8 hr

1

2

3

2

3

4

5

Case Study 11 Hyperemesis

Gravidarum

Orders requiring calculations: IV D5 1–2 NS at 150 mL/hr and 100 mL/hr; droperidol (Inapsine) 1 mg IV; metoclopramide (Reglan) 20 mg IV in 50 mL of D5W to infuse over 15 min; diphen hydramine(Benadryl) 25 mg; dexamethasone (Deca dron) 4 mg IV

1

2

3

4

5


11 mL 150 mg 11 × 15 165�

6.6 mg

hr 250 mL 25 25 hr

10 mg mL 10� 1 mL

10 mg 10


25 mg 25

80 mg mL 8� 8 mL

10 mg 1

150 mL 20 gtt 1 hr 150 × 2 × 1 300�

50gtt


100 mL 20 gtt 1 hr 100 × 2 × 1 200�

33.3 or 33 gtt


1 mg mL 1� 0.4 mL

2.5 mg 2.5

50 mL 60 min 50 × 60 3000�

200 mL

15 min 1 hr 15 × 1 15 hr

25 mg mL 25� 2.5 mL

10 mg 10

4 mg mL 4� 1 mL

4 mg 4


500 mg 50

5 mg mL 5� 0.25 mL

20 mg 20

250 mL 60 min 250 × 6 1500�

500 mL

30 min 1 hr 3 × 1 3 hr

1 g 1000 mL 1 × 100 100�

25 mL

hr 40 g 4 4 hr

10 mg capsule 10� 1 capsule

10 mg 10

250 mL 60 min 250 × 6 1500�

750 mL

20 min 1 hr 2 × 1 2 hr

2 g 250 mL 2 × 250 500�

125 mL

hr 4 g 4 4 hr

0.25 mg mL 0.25� 0.25 mL

1 mg 1

20 mg capsule 2� 2 capsules

10 mg 1


4

5

Case Study 14 Cystic Fibrosis

Orders requiring calculations: IV 0.9% normal saline at75 mL/hr; Tagamet 30 mg PO; clindamycin 10 mg/kgIV; terbutaline 2.5 mg PO; tobramycin 1.5 mg/kg IV

1

2

3

4

5

Case Study 15 Respiratory Syncytial

Virus (RSV)

Orders requiring calculations: Acetaminophen elixir 120mg PO; aminophylline 5 mg/kg to infuse over 30 minand 0.8 mg/kg/hr IV; RespiGam 750 mg/kg IV; Pedi-apred 1.5 mg/kg/day in three divided doses PO; ampi-cillin 100 mg/kg/day in divided doses every 6h IV

1

2

3

4

5

Case Studies 2 7 1

12 mg mL 12� 2 mL

6 mg 6

1000 mL 1000�

125 mL

8 hr 8 hr

75 mL 15 gtt 1 hr 75 × 15 × 1 1125�

18.75 or 19 gtt


295 mg mL 295� 1.96 or 2 mL

150 mg 150

52 mL 60 min 52 × 6 312�

156 mL

20 min 1 hr 2 × 1 2 hr

2.5 mg tablet 2.5� 1 tablet

2.5 mg 2.5

1.5 mg 1 kg 65 lb 1.5 × 1 × 65 97.5� 44.31 or 44 mg

kg 2.2 lb 2.2 2.2

44 mg mL 44� 1.1 or 1 mL

40 mg 40

51 mL 60 min 51 × 6 306�

102 mL

30 min 1 hr 3 × 1 3 hr

120 mg 5 mL 5� 5 mL

120 mg

5 mg 1 kg 30 lb 5 × 1 × 30 150� 68.18 or 68.2 mg

kg 2.2 lb 2.2 2.2

68.2 mg 100 mL 60 min 68.2 × 10 × 6 4092�

54.56 or 54.6 mL

30 min 250 mg 1 hr 3 × 25 × 1 75 hr

0.8 mg 100 mL 1 kg 30 lb 0.8 × 100 × 1 × 3 240�

4.36 or 4.4 mL

kg/ hr 250 mg 2.2 lb 25 × 2.2 55 hr

750 mg 1 kg 30 lb 750 × 1 × 30 22,500�

10,227.27

kg 2.2 lb 2.2 2.2 or 10,227.3 mg

1.5 mg 5 mL 1 kg 30 lb day 1.5 × 5 × 1 × 30 225�

2.27 or 2.3 mL


100 mg 1 kg 30 lb day 100 × 1 × 30 3000�

340.9 or 341 mg

kg/day 2.2 lb 4 doses 2.2 × 4 8.8 dose

341 mg 10 mL 1 g 341 × 1 × 1 341� 3.41 or 3.4 mL

1 g 1000 mg 1 × 100 100

53 mL 60 min 53 × 6 318�

106 mL

30 min 1 hr 3 × 1 3 hr

30 mg tablet 1 kg 65 lb day 3 × 1 × 65 195�

1.1 or 1 tablet


10 mg 1 kg 65 lb 10 × 1 × 65 650� 295.45 or 295 mg

kg 2.2 lb 2.2 2.2


Case Study 16 Leukemia

Orders requiring calculations: IV D5W/NS with 20 mEq KCl 1000 mL over 8 h; allopurinol 200 mgPO; Fortaz 1 g IV; aztreonam 2 g IV; Flagyl 500 mg IV

1

2

3

4

5

Case Study 17 Sepsis

Orders requiring calculations: NG breast milk withsterile water 120 mL per feeding; IV D10 and 20%lipids 120 mL/kg/day; aminophylline 5 mg/kg IV every 6h; cefotaxime 50 mg/kg every 12h; van co -mycin 10 mg/kg/dose every 12h

1

2

3

4

5

Case Study 18 Bronchopulmonary

Dysplasia

Orders requiring calculations: NG feedings with Spe-cial Care with Iron 120 KCal/kg/day; chloro thiazide10 mg/kg/day; Fer-In-Sol 2 mg/kg/day; vi tamin E 25units/kg/day in divided doses every 12h; caffeine cit-rate 5 mg/kg/dose daily

1

2

3


1000 mL 1000�

125 mL

8 hr 8 hr


100 mg 1

1 g 10 mL� 10 mL

1 g

60 mL 60 min 60 × 6 360�

120 mL

30 min 1 hr 3 × 1 3 hr

2 g 10 mL� 10 mL

2 g

110 mL 60 min 110�

110 mL

60 min 1 hr 1 hr

500 mg 100 mL 100�

100 mL

1 hr 500 mg 1 hr

120 mL day 3 hr 120 × 3 360�

15 mL

day 24 hr feeding 24 24 feeding

120 mL day 1 kg 2005 g 12 × 1 × 2005 24,060�

10.025 or 10 mL

kg/day 24 hr 1000 g 24 × 100 2400 hr

5 mg 1 kg 2005 g 5 × 1 × 2005 10025� 10.025 or 10 mg

kg 1000 g 1000 1000

10 mg 10 mL 60 min 10 × 10 × 6 600�

24 mL

5 min 50 mg 1 hr 5 × 5 × 1 25 hr

50 mg 1 kg 2005 g 5 × 1 × 2005 10025� 100.25 or 100 mg

kg 1000 g 100 100

100 mg mL 60 min 10 × 6 60�

5 mL

30 min 40 mg 1 hr 3 × 4 × 1 12 hr

10 mg 1 kg 2005 g 1 × 1 × 2005 2005�

20.05 or 20 mg

kg/ dose 1000 g 100 100 dose

20 mg 1 mL 20 × 1 20�

4 mL

1 hr 5 mg 1 × 5 5 hr

120 kcal 1 kg 996 g 12 × 1 × 996 11,952�

119.52 or 120 kcal

kg/ day 1000 g 100 100 day

120 kcal oz 30 mL 120 × 30 3600�

150 mL

day 24 kcal 1 oz 24 × 1 24 day

10 mg 1 kg 996 g 1 × 1 × 996 996�

9.96 or 10 mg

kg/ day 1000 g 100 100 day

10 mg 5 mL 1 × 5 5�

0.2 mL

day 250 mg 25 25 day

2 mg 1 kg 996 g 2 × 1 × 996 1992�

1.99 or 2 mg

kg/ day 1000 g 1000 1000 day

2 mg 0.6 mL 2 × 0.6 1.2�

0.08 mL

day 15 mg 15 15 day


4

5

Case Study 19 Cerebral Palsy

Orders requiring calculations: Lactulose 3 g PO tid;Depakote 30 mg/kg/day PO in three divided doses;diazapam 2.5 mg PO daily; chlorothiazide 250 mg POdaily; Dilantin 5 mg/kg/day PO in three divided doses

1

2

3

4

5

Case Study 20 Hyperbilirubinemia

Orders requiring calculations: Albumin 5% infusion 1 g/kg 1 hr before exchange; ampicillin 100 mg/ kg/doseIV every 12h; gentamicin 2.5 mg/kg/dose IV every 12h;120 mL/kg/day formula; IV D10W 120 mL/ kg/day

1

2

3

4

5

Case Study 21 Spontaneous Abortion

Orders requiring calculations: Rhogam 300 mcg IM; IVD5/0.9% NS at 100 mL/hr; oxytocin (Pitocin) 10 units infused at 20 mL/min; meperidine 50 mg IMevery 4h; ibuprofen 400 mg PO

1

2

3

Case Studies 2 7 3

25 units 1 kg 996 g day 25 × 1 × 996 24,900�

12.45 or 12.5 units

kg/day 1000 g 2 doses 1000 × 2 2000 dose

12.5 units mL 12.5�

0.18 or 0.2 mL

dose 67 units 67 dose

5 mg 1 kg 996 g day 5 × 1 × 996 4980�

1.24 or 1.2 mg

kg/day 1000 g 4 doses 1000 × 4 4000 dose

1.2 mg mL 1.2�

0.12 or 0.1 mL

dose 10 mg 10 dose

3 g 15 mL 3 × 15 45� 4.5 or 5 mL

10 g 10 10

30 mg 38 kg day 30 × 38 1140�

380 mg

kg/day 3 doses 3 3 dose

380 mg tablet 380� 3.04 or 3 tablets

125 mg 125


5 mg 5


250 mg 250

5 mg 38 kg day 5 mL 5 × 38 × 5 950�

2.53 or 2.5 mL

kg/day 3 dose 125 mg 3 × 125 375 dose

1 g 1 kg 2210 g 1 × 1 × 221 221�2.21 or 2.2 g

kg 1000 g 100 100

100 mg 1 kg 2210 g 1 × 221 221�

221 mg

kg/ dose 1000 g 1 1 dose

221 mg 5 mL 221 × 5 1105�4.42 or 4.4 mL

250 mg 250 250

4 mg 1 kg 2210 g 4 × 1 × 221 884�

8.84 or 8.8 mg

kg/ dose 1000 g 100 100 dose

8.8 mg mL 8.8� 4.4 mL

2 mg 2

120 mL 1 kg 2210 g 12 × 1 × 221 2652�

265.2 or 265 mL

kg/day 1000 g 10 10 day

120 mL 1 kg 2210 g day 12 × 1 × 221 2652�

11.05 or 11 mL

kg/day 1000 g 24 hr 10 × 24 240 hr

20 mU 500 mL 1 U 60 min 2 × 5 × 1 × 6 60�

60 mL

min 10 U 1000 mU 1 hr 1 × 1 × 1 1 hr

300 mcg 1 ml 1� 1 mL

300 mcg

100 mL 15 gtt 1 hr 10 × 15 × 1 150�

25 gtt



4

5

Case Study 22 Bipolar Disorder

Orders requiring calculations: IV 0.9% NS at 75 mL/ hr;lithium 300 mg, lithium 300 mg; clonazepam 0.5 mg;clonazepam 1 mg; doxepin 25 mg

1

2

3

4

5

Case Study 23 Anorexia Nervosa

Orders requiring calculations: IV 1000 mL/8 hr; olanza-pine (Zyprexa) 10 mg; fluoxetine (Prozac) 60 mg/day;Amitriptyline 25 mg; Cyproheptadine 32 mg/day

1

2

3

4

5

Case Study 24 Clinical Depression

Orders requiring calculations: IV 100 mL/hr; glyco -pyrrolate (Robinul) 4.4 mcg/kg; Zoloft 50 mg PO everyAM; Sinequan 25 mg PO tid; Parnate 30 mg/day PO in2 divided doses

1

2

3

4

5


50 mg mL 5� 0.5 mL

100 mg 10

300 mg capsule 30� 2 capsules

150 mg 15


0.5 mg 0.5


0.5 mg 0.5


25 mg 25


200 mg 2

75 mL 20 gtt 1 hr 75 × 2 × 1 150�

25 gtt



5 mg 5

25 mg 5 mL 25 × 5 125�12.5 mL

10 mg 10 10

8 mg 5 mL 8 × 5 40� 20 mL

2 mg 2 2

32 mg day�

8 mg

day 4 doses dose


50 mg 5

100 mL 10 gtt 1 hr 10 × 10 100�

16.6 or 17 gtt


4.4 mcg mL 1 kg 175 lb 4.4 × 1 × 175 770� 1.75 or 1.8 mL

kg 200 mcg 2.2 lb 200 × 2.2 440


25 mg 25

30 mg day 30�

15 mg

day 2 doses 2 dose


10 mg 10

1000 mL�

125 mL

8 hr hr

60 mg 5 mL 6 × 5 30� 15 mL

20 mg 2 2


Case Study 25 Alzheimer’s Disease

Orders requiring calculations: IV 1000 mL/8 hr;donepezil (Aricept) 5 mg; thioridazine (Mellaril) 25 mg; imipramine (Tofranil) 50 mg; temazepam(Restoril) 7.5 mg

1

2

3

4

5

Case Study 26 Otitis Media

Orders requiring calculations: Amoxicillin 45/kg/ day,Acetaminophen 120 mg, Ibuprofen 5 mg/kg, Zyrtec2.5 mg, Pedialyte 75 mL/kg

1

2

3

4

5

Case Study 27 Seizures

Orders requiring calculations: IV D5W/0.45% NS,Dilantin 2 mg/kg/min, Diazepam 0.3/kg, Acet amino -phen 320 mg, Ibuprofen 7.5 mg/kg

1

2

3

4

5

Case Study 28 Fever of Unknown Origin

Orders requiring calculations: Acetaminophen 400 mg,Ibuprofen 7.5 mg/kg, IV D5W/0.45% NS mL/hr andgtt/min, Unasyn 1500 mg

1

2

3

Case Studies 2 7 5

1000 mL 10 gtt 1 hr 100 × 10 × 1 1000�

20.83 or 21 gtt

8 hr mL 60 min 8 × 6 48 min


5 mg 5


25 mg 25


25 mg 25


15 mg 15

45 mg 5 mL day 1 kg 23 lb 45 × 5 × 1 × 23 5175�

9.4 or 9 mL

kg/day 125 mg 2 doses 2.2 lb 125 × 2 × 2.2 550 dose

120 mg mL 12� 1.2 or 1 mL

100 mg 10

5 mg 5 mL 1 kg 23 lb 5 × 5 × 1 × 23 575� 2.6 or 3 mL

kg 100 mg 2.2 lb 100 × 2.2 220

2.5 mg mL 2.5� 2.5 or 3 mL

1 mg 1

500 mL 500�

62.5 or 63 mL

8 hr 8 hr

2 mg 50 mL 1 kg 60 lb 60 min 2 × 50 × 6 × 6 3600�

109 mL

kg/15 min 100 mg 2.2 lb 1 hr 15 × 1 × 2.2 33 hr

0.3 mg mL 1 kg 60 lb 0.3 × 1 × 60 18� 1.63 or 1.6 mL

kg 5 mg 2.2 lb 5 × 2.2 11

320 mg mL 32� 3.2 or 3 mL

100 mg 10

7.5 mg 5 mL 1 kg 60 lb 7.5 × 5 × 1 × 6 225� 10.2 or 10 mL

kg 100 mg 2.2 lb 10 × 2.2 22

400 mg 15 mL 4 × 15 60� 12 mL

500 mg 5 5

7.5 mg 5 mL 1 kg 80 lb 7.5 × 5 × 1 × 8 300� 13.6 or 14 mL

kg 100 mg 2.2 lb 10 × 2.2 22

500 mL 500�

125 mL

4 hr 4 hr

75 mL 1 kg 23 lb 75 × 1 × 23 1725�

98 mL

kg/8 hr 2.2 lb 8 × 2.2 17.6 hr


4

5

Case Study 29 TURP with CBI

Orders requiring calculations: IV D5W/.45% NS inmL/hr and gtt/min, Cipro 400 mg, Colace 100 mg,dimenhydrinate 25 mg

1

2

3

4

5

Case Study 30 Hypercholesterolemia

Orders requiring calculations: Chantix 0.5 mg fordays 1–8, Lipitor 20 mg, cholestyramine resin 4 g,niacin 1.5 g/day

1

2

3

4

5

Case Study 31 Hypertension

Orders requiring calculations: mL/meal of fluids,nifedipine 60 mg, Colace 100 mg, hydrochloro thiazide25 mg, Weight gain

1

2

3

4

5

Case Study 32 Diabetic Ketoacidosis

Orders requiring calculations: IV 0.9% NS 20 mL/ kg/hr, regular insulin 0.15 units/kg, regular insulin 0.1 unit/kg/hr, IV D5W/0.45% NS, ampicillin sodium500 mg

1


1000 mL 1000�

125 mL

8 hr 8 hr

1000 mL 20 gtt 1 hr 1000 × 2 × 1 2000�

41.6 or 42 gtt

8 hr mL 60 min 8 × 6 48 min

400 mg 200 mL 60 min 200�

200 mL

60 min 400 mg 1 hr 1 hr


100 mg 100

25 mg mL 25� 0.5 mL

50 mg 50


0.5 mg 0.5


0.5 mg 0.5

2 L day 1000 mL 2 × 1000 2000�

666.6 or 667 mL

day 3 meals 1 L 3 × 1 3 meal


30 mg 3


100 mg 100

5 kg 2.2 lb 5 × 2.2 11� 11 lb

1 kg 1 1

1000 mL 1000�

125 mL

8 hr 8 hr

500 mL 1 hr 60 gtt 500 × 1 500�

125 gtt

4 hr 60 min mL 4 4 min

1500 mg 50 mL 1 g 60 min 15 × 5 × 6 450�

100 mL

30 min 1.5 g 1000 mg 1 hr 3 × 1.5 × 1 4.5 hr


10 mg 1

4 g 2 doses 4 × 2 8�

8 g

dose day day

1.5 g tablet 1000 mg 1.5 × 10 15�

3 tablets

day 500 mg 1 g 5 × 1 5 day

25 mg tablet 25� 0.5 tablet

50 mg 50


Case Study 34 Fluid Volume Deficit

Orders requiring calculations: IV 0.9% NS/2.5% Dex-trose 50 mL/kg, Acetaminophen 400 mg, Ibuprofen7.5 mg/kg, mL/hr of PO fluids, mL/hr of Pedialyte

1

2

3

4

5

Case Study 35 Increased Intracranial

Pressure

Orders requiring calculations: IV 0.9% NS, Dilantin 10mg/kg, Mannitol 0.25 g/kg, Dexamethasone 10 mg,Furosemide 0.5 mg/kg

1

2

3

4

5

2

3

4

5

Case Study 33 End-Stage Renal

Failure

Orders requiring calculations: Furosemide 120 mg,Zaroxolyn 10 mg, Vasotec 2.5 mg, Epogen 100 units/kg,Calcium Carbonate 10 g/day

1

2

3

4

5

Case Studies 2 7 7


80 mg 8


5 mg 5


2.5 mg 2.5

100 units mL 1 kg 140 lb 1 × 1 × 14 14� 1.59 or 1.6 mL

kg 4000 units 2.2 lb 4 × 2.2 8.8

10 g tablet 1000 mg day 10 × 10 100�

2.2 or 2 tablets

day 1500 mg 1 g 3 meals 15 × 1 × 3 45 meals

7.5 mg 5 mL 1 kg 35 lb 7.5 × 5 × 1 × 35 1312.5� 5.9 or 6 mL

kg 100 mg 2.2 lb 100 × 2.2 220

1.5 oz 30 mL 35 lb 1.5 × 30 × 35 1575�

65.6 or 66 mL

lb/24 hr 1 oz 24 × 1 24 hr

53 oz 30 mL 53 × 30 1590�

66.2 or 66 mL

24 hr 1 oz 24 × 1 24 hr

1000 mL 1000�

100 mL

10 hr 10 hr

10 mg 20 mL 75 kg 1 × 2 × 75 150� 15 mL

kg 1000 mg 10 10

0.25 g 500 mL 75 kg 0.25 × 5 × 75 93.7�

93.7 or 94 mL

kg/ hr 100 g 1 1 hr

10 mg 5 mL 1 × 5 5� 0.41 or 0.4 mL

120 mg 12 12

0.5 mg mL 75 kg 0.5 × 75 37.5� 3.75 or 3.7 mL

kg 10 mg 10 10

0.1 unit 250 mL 1 kg 125 lb 0.1 × 1 × 125 12.5�

5.68 or 5.7 mL

kg/ hr 250 units 2.2 lb 2.2 2.2 hr

10 mL 1 kg 125 lb 10 × 1 × 125 1250�

568.1 or 568 mL

kg/ hr 2.2 lb 2.2 2.2 hr

500 mg 100 mL 1 g 60 min 5 × 10 × 6 300�

100 mL

30 min 1 g 1000 mg 1 hr 3 × 1 × 1 3 hr

0.15 units 250 mL 1 kg 125 lb 0.15 × 1 × 125 18.75� 8.52 or 8.5 mL

kg 250 units 2.2 lb 2.2 2.2

50 mL 1 kg 35 lb 50 × 1 × 35 1750�

198.8 or 199 mL

kg/4 hr 2.2 lb 4 × 2.2 8.8 hr

400 mg mL 4� 4 mL

100 mg 1


5

Case Study 38 Acute Asthma Attack

Orders requiring calculations: IV D5W/1/2 NS at 1000mL/10 hr, weight 176 lb, Solu-Medrol 80 mg,azithromycin (Zithromax) 500 mg, cimetidine (Taga-met) 300 mg

1

2

3

4

5

Case Study 39 Right Total Hip

Replacement

Orders requiring calculations: IV D5W/NS at 1000mL/10 hr, atenolol 50 mg, lisinopril 5 mg, enoxaparin(Lovenox) 40 mg, dimenhydrinate 50 mg, and morphine 10 mg

1

2

3

40 mg 0.8 mL 4 × 0.8 3.2� 0.4 mL

80 mg 8 8

500 mg capsular 50� 2 capsulars

250 mg 25

176 lb 1 kg 176 × 1 176� 80 kg

2.2 lb 2.2 2.2

61 mL 60 min 61 × 6 366�

122 mL

30 min 1 hr 3 × 1 3 hr


100 mL 15 gtt 1 hr 10 × 15 × 1 150�

25 gtt


450 mL 450�

150 mL

3 hr 3 hr

2 mg 1 kg 150 lb 2 × 1 × 150 300� 136.3 or 136 mg

kg 2.2 lb 2.2 2.2

5 mcg mL 1 kg 150 lb 5 × 1 × 15 75�

1.1 or 1 mL

kg / day 300 mcg 2.2 lb 30 × 2.2 66 day

1000 mL 1000�

125 mL

8 hr 8 hr

300 mg 50 mL 60 min 50 × 6 300�

150 mL

20 min 300 mg 1 hr 2 × 1 2 hr

50 mg 10 mL 1 g 40 kg 5 × 1 × 1 × 4 20� 10 mL

kg 2 g 1000 mg 2 × 1 2

25 mg mL 25� 0.5 mL

50 mg 50

88 lb 1 kg 88 × 1 88� 40 kg

2.2 lb 2.2 2.2

3 mg mL 3� 0.75 or 0.8 mL

4 mg 4

1000 mL 1000�

100 mL

10 hr 10 hr

80 mg 2 mL 80 × 2 160� 1.28 or 1.3 mL

125 mg 125 125

50 mL 60 min 50 × 6 300�

150 mL

20 min 1 hr 2 × 1 2 hr


25 mg 25


2.5 mg 2.5

Case Study 36 Breast Cancer

Orders requiring calculations: IV D5W/1/2 NS at 100mL/hr, filgrastim (Neupogen) 5 mcg/kg/day, metoclo-pramide (Reglan) 2 mg/kg, 1 unit of PRBC, anddiphenhydramine (Benadryl) 25 mg

1

2

3

4

5

Case Study 37 Severe Abdominal Pain

Orders requiring calculations: weight, IV D5W/0.45% NS@ 1000 mL/8 hr, Cleocin 300 mg, Claforan 50 mg/kg,morphine sulfate 3 mg

1

2

3

4


3

4

5

Case Study 42 Chest Pain

Orders requiring calculations: IV nitroglycerin 10 mcg/min, ASA 160 mg, and morphine 2.5 mg

1

2

3

4

5

Case Study 43 Pneumococcal

Meningitis

Orders requiring calculations: Weight lb to kg, IVbolus, acetaminophen 15 mg/kg/dose, ceftriaxone 100mg/kg/dose, and vancomycin 60 mg/kg/day

1

2

4

5

Case Study 40 Colon Resection

Orders requiring calculations: IV NS with KCl 20 mEq/L at 1000 mL/12 hr, cefoxitin 1 g, Ranitidine 50mg, tamsulosin (Flomax) 0.8 mg, and Os-Cal 1.25 g

1

2

3

4

5

Case Study 41 Left Total Knee

Replacement

Orders requiring calculations: IV D5/LR with 20 mEqKCl, cefazolin 1g IV, cefazolin 500 mg, enoxaparin(Lovenox) 30 mg, and ferrous sulfate 0.3 g

1

2

0.8 mg capsule 0.8� 2 capsules

0.4 mg 0.4

100 mL 60 min 100 × 6 600� 300

mL

20 min 1 hr 2 × 1 2 hr

50 mg mL 5� 1 mL

50 mg 5

50 mL 60 min 50 × 6 300� 100

mL

30 min 1 hr 3 × 1 3 hr

Case Studies 2 7 9

1000 mL 1000� 83.3 or 83

mL

12 hr 12 hr

10 mg mL 10� 1.25 or 1.3 mL

8 mg 8


80 mg 8


1250 mg 1 g 125 × 1 125

1000 mL 1000�125

mL

8 hr 8 hr

100 mL 60 min 100 × 6 600� 200

mL

30 min 1 hr 3 × 1 3 hr

50 mL 60 min 50 × 6 300� 100

mL

30 min 1 hr 3 × 1 3 hr

30 mg 0.4 mL 3 × 0.4 1.2� 0.3 mL

40 mg 4 4

0.3 g tablet 1000 mg 0.3 × 10 3� 1 tablet

300 mg 1 g 3 × 1 3

10 mcg 250 mL 1 mg 60 min 1 × 25 × 1 × 6 150� 3

mL

min 50 mg 1000 mcg 1 hr 5 � 10 � 1 50 hr

15 mL 50 mg 1000 mcg 1 hr 15 × 5 × 100 × 1 7500� 50

mcg

hr 250 mL 1 mg 60 min 25 × 1 × 6 150 min

2.5 mg mL 2.5� 0.5 mL

5 mg 5

7.5 mg mL 7.5� 1.5 mL

5 mg 5

44 lb 1 kg 44� 20 kg

2.2 lb 2.2

10 mL 20 kg 10 × 20� 200 mL

kg


4

5

Case Study 45 C-Section Delivery

Orders requiring calculations: Zidovudine 2 mg/kg/dose IV, zidovudine 1 mg/kg/hr continuous IV infu-sion, cefazolin 1 g IVPB, and metoclopramide (Reglan)10 mg IV push

1

2

3

4

5

3

4

5

Case Study 44 Diabetic Ketoacidosis

Orders requiring calculations: Weight lb to kg, IVbolus, IV NS with KCl 20 mEq/L, regular insulin 0.1 units/kg/hr, and ondansetron IV push 0.1 mg/kg

1

2

3

164 lb 1 kg 164 × 1 164� 74.5 kg

2.2 lb 2.2 2.2


15 mg 20 kg 2.5 mL 15 � 2 × 2.5 75� 9.3 or 9

mL

kg/ dose 80 mg 8 8 dose

1000 mg 50 mL 1 g 60 min 5 × 60 300� 100

mL

30 min 1 g 1000 mg 1 hr 3 × 1 3 hr

50 mg 20 kg 50 × 20 1000� 1000

mg

kg/dose dose

300 mg 100 mL 60 min 30 × 10 × 6 1800� 120

mL

30 min 500 mg 1 hr 3 × 5 × 1 15 hr

60 mg 20 kg day 60 × 20 1200� 300

mg

kg/day 4 doses 4 4 dose

54 lb 1 kg 54� 24.5 kg

2.2 lb 2.2

10 mg mL 10� 2 mL

5 mg 5

10 ml 24.5 kg 10 × 24.5 245� 245 mL

kg

3.5 mL 24.5 kg 3.5 × 24.5 85.7� 85.7 or 86

mL

kg/ hr hr

0.1 unit 24.5 kg 250 mL 0.1 × 24.5 × 250 612.5� 24.5

mL

kg/ hr 25 units 25 25 hr

0.1 mg 24.5 kg mL 0.1 � 24.5 2.45� 1.2 or 1 mL

kg 2 mg 2 2

2 mg 74.5 kg 50 ml 2 × 74.5 × 5 745� 37.2 or 37 mL

kg 200 mg 20 20

1 mg 100 mL 74.5 kg 1 × 1 × 74.5 74.5� 18.6 or 19

mL

kg/ hr 400 mg 4 4 hr

1 g 60 min 100 mL 1000 mg 6 × 100 600� 200

mL

30 min 1 hr 1000 mg 1 g 3 × 1 3 hr


Comprehensive Post-Test

S E C T I O N 4

LWBK732_Sec04_p281-286:NEW.qxd 11/20/10 2:10 PM Page 281

Comprehensive Post-Test 2 8 3

Comprehensive Post-Test

Name Date

1. Order: Lopressor 12.5 mg PO daily for severe heart failure.

Supply: Lopressor 25 mg/tablets


2. Order: Synthroid 0.2 mg PO daily for hypothyroidism.

Supply: Synthroid 200 mcg/tablets


3. Order: Micro K 30 mEq PO daily for hypokalemia.

Supply: Micro K 10 mEq/capsules

❊ How many capsules will you give?

4. Order: Phenergan 12.5 mg IV every 4 hours for nausea.

Supply: Phenergan 25 mg/mL

❊ How many milliliters will you give?

5. Order: 1000 mL of D5W/0.45 NS to infuse over 12 hours


❊ Calculate the number of drops per minute.

6. Order: Heparin 2500 units/hr IV for thrombophlebitis.

Supply: Heparin 25,000 units/500 mL

❊ Calculate milliliter per hour to set the IV pump.

7. Order: Infuse Heparin at 45 mL/hr IV for thrombophlebitis.

Supply: Heparin 25,000 units/500 mL

❊ How many units per hour is the patient receiving?

8. Order: Infuse 250 mL bolus of 0.9% NS at 33 gtt/min

Supply: 250 mL 0.9% NS with 20 gtt/mL tubing

❊ How many hours will it take to infuse the IV bolus?



2 8 4 S E C T I O N 4 Comprehensive Post-Test

9. Order: Pentamidine: 4 mg/kg IV daily for 14 days for patient weighing 130 lb

for severe Pneumocystis carinii pneumonia.

Supply: Pentamidine 300 mg/250 mL D5W to infuse over 60 min.


10. Order: Naloxone (Narcan) 0.01 mg/kg IV for narcotic overdose for child

weighing 35 kg.

Supply: Naloxone (Narcan) 0.4 mg/mL


11. Order: Epogen 150 units/kg SQ three times weekly due to anemia

secondary to chemotherapy for a patient weighing 80 kg.

Supply: Epogen 20,000 units/mL


12. Order: Acyclovir 5 mg/kg IV every 8 hours for 7 days for cutaneous herpes

simplex for a patient weighing 70 kg.

Supply: Acyclovir 1-g vial


and further dilute in 100 mL 0.9% NS and infuse over 1 hour.

❊ How many milliliters will you draw from the vial after reconstitution?


❊ Calculate the drops per minute with a drop factor of 20 gtt/mL.

13. Order: Vancomycin 1 g IV every 12 hours for severe staphylococcal infection.

Supply: Vancomycin 5-g vial


and further dilute in 250 mL of D5W and infuse over 60 minutes.

❊ How many milliliters will you draw from the vial after reconstitution?


❊ Calculate the drops per minute with a drop factor of 10 gtt/mL.


Comprehensive Post-Test 2 8 5

14. Order: Regular Insulin 8 units/hours for hyperglycemia

Supply: Regular Insulin 100 units/250 mL 0.9% NS

❊ Calculate milliliters per hours to set the IV pump.

15. Order: Nitroprusside 0.8 mcg/kg/min for hypertensive crisis.

Supply: Nitroprusside 50 mg/500 mL D5W

The patient weighs: 143 lb

❊ Calculate milliliters per hour to set the IV pump.

16. Order: Mycostatin oral suspension 500,000 units swish/swallow for oral

candidiasis.

Supply: Mycostatin 100,000 units/mL

❊ How many teaspoons will you give?

17. Order: Dilaudid 140 mL/hr

Supply: Dilaudid 30 mg/1000 mL D5/NS

❊ Calculate milligrams per hour the patient is receiving.

18. Order: Aminophylline 44 mg/hr for status asthmaticus.

Supply: Aminophylline 1 g/250 mL D5W

❊ Calculate milliliters per hour to set the IV pump.

19. Order: 1000 mL NS to infuse at 60 gtt/min


❊ Calculate how many hours it will take for the IV to infuse.

20. Order: Dopamine (Intropin) 5 mcg/kg/min IV for cardiogenic shock

secondary to myocardial infarction.

Supply: Dopamine 200 mg/250 mL D5W



Dimensional analysis is a problem-solvingmethod based on the principles of cognitive theory.Bruner (1960) theorized that learning is dependent onhow information is structured, organized, and con-ceptualized. He proposed a cognitive learningmodel that emphasized the acquisition, organiza-tion (structure), understanding, and transfer ofknowledge—focusing on “how” to learn, rather than“what” to learn. Learning involves associations estab-lished according to the principles of continuity and repetition.

Dimensional analysis (also called factor-labelmethod, conversion-factor method, units analysis,and quantity calculus) provides a systematic way toset up problems and helps to organize and evaluatedata. Hein (1983) emphasized that dimensionalanalysis gives a clear understanding of the principlesof the problem-solving method that correlates withthe ability to verbalize what steps are taken leading tocritical thinking. He described dimensional analysisas a useful method for solving a variety of chemistry,physics, mathematics, and daily life problems. Heidentified that dimensional analysis is often the prob-lem-solving method of choice because it provides astraightforward way to set up problems, gives a clearunderstanding of the principles of the problem, helpsthe learner to organize and evaluate data, and assistsin identifying errors if the setup of the problem isincorrect.

Goodstein (1983) described dimensional analy-sis as a problem-solving method that is very sim-ple to understand, reduces errors, and requiresless conceptual reasoning power to understand

than does the ratio–proportion method. She ex -pressed that “even though the ratio–proportionmethod was at one time the primary problem-solvingmethod, it has been largely replaced by a dimensionalanalysis approach in most introductory chemistrytextbooks . . . this method condenses multi-stepproblems into one orderly extended solution.”

Peters (1986) identified dimensional analysis as amethod used for solving not only chemistry problemsbut also a variety of other mathematical problemsthat require conversions. He defined dimensionalanalysis as a method that can be used whenever twoquantities are directly proportional to each other andone quantity must be converted to the other using aconversion factor or conversion relationship.

Literature that has examined the quality of highereducation and professional education in the UnitedStates (National Institute of Education, 1984) rec-ommends that educators increase the emphasis of theintellectual skills of problem solving and criticalthinking. Also recommended is an increased empha-sis on the mastery of concepts rather than specificfacts. Other literature on curriculum revolution innursing (Bevis, 1988; Lindeman, 1989; Tanner,1988) recommends that learning not be character-ized merely as a change in behavior or the acquisitionof facts, but in seeing and understanding the signifi-cance of the whole. Because it focuses on “how” tolearn, rather than “what” to learn, dimensionalanalysis supports conceptual mastery and higher-levelthinking skills that have become the core of the cur-riculum change that is sweeping through all levels ofeducation and, most importantly, nursing education.

A P P E N D I X

Educational Theory of Dimensional Analysis

2 8 7

LWBK732_APP_p287-288:Appendix 11/22/10 2:46 PM Page 287

Bibliography

Bevis, E. (1988). New directions for a new age. In National League forNursing, Curriculum revolution: Mandate for change (pp. 27–52). NewYork: National League for Nursing (Pub. No. 15–2224).

Bruner, J. (1960). The process of education. New York: Random House.Craig, G. (1995). The effects of dimensional analysis on the medication

dosage calculation abilities of nursing students. Nurse Educator, 20 (3),14–18.

Craig, G. P. (1997). The effectiveness of dimensional analysis as a prob-lem-solving method for medication calculations from the nursingstudent perspective. Unpublished doctoral dissertation, Drake Uni-versity, Des Moines, IA.

Goodstein, M. (1983). Reflections upon mathematics in the introductorychemistry course. Journal of Chemical Education, 60(8), 665–667.

Hein, M. (1983). Foundations of chemistry (4th ed.). Encino, CA: Dick-enson Publishing Company.

Lindeman, C. (1989). Curriculum revolution: Reconceptualizing clini-cal nursing education. Nursing and Health Care, 10(1), 23–28.

National Institute of Education. (1984). Involvement in learning: Realizingthe potential of American higher education. Washington, DC: NationalInstitute of Education.

Peters, E. (1986). Introduction to chemical principles (4th ed.). Saratoga, CA:Saunders College Publishing.

Tanner, C. (1988). Curriculum revolution: The practice mandate. Nursingand Health Care, 9(8), 426–430.

2 8 8 A P P E N D I X Educational Theory of Dimensional Analysis

LWBK732_APP_p287-288:Appendix 11/22/10 2:46 PM Page 288

2 8 9

A

abacavir (Ziagen), dosage calculation forone-factor, 193two-factor, 203

abortion, spontaneous, case study of, 245–246acetaminophen, see Tylenol (acetaminophen)acquired immunodeficiency syndrome (AIDS), case study of, 231–232 acyclovir

dosage calculation for, two-factor, 137, 201IV therapy considerations, 132

adalat (nifedipine), dosage calculation for, one-factor,181administration routes, 69

enteral, 84–90intravenous (see intravenous therapy)parenteral, 90–96

advil (ibuprofen), dosage calculation for, 74–75AIDS (acquired immunodeficiency syndrome), case study of,

231–232Alzheimer’s disease, case study of, 249amikacin (Amikin), dosage calculation for, three-factor, 209 aminophylline, dosage calculation for, 212

IV therapy, 126–128three-factor, 165, 173

amiodarone (Cordarone IV), dosage calculation for, 213amoxicillin, dosage calculation for, 213ampicillin. see Unasyn (ampicillin) amrinone, dosage calculation for, three-factor, 164ancef, dosage calculation for

three-factor, 159two-factor, 123, 145

anemia, sickle cell, case study of, 232–233anorexia nervosa, case study of, 247–248anticoagulants, administration of, 91apothecaries’ measurement system, 33–35

abbreviations, 33b, 34bdefined, 33other system equivalents for, 39t, 40, 43volume in, 33, 34b, 34f, 39tweight in, 33, 34b, 34f, 39t

Arabic number system, 6, 6tconverting between Roman and, 3, 6–9, 18, 21defined, 6

ascorbic acid, dosage calculation for, 210aspirin, dosage calculation for, 73–74 atenolol (Tenormin), dosage calculation for, 213 atropine sulfate, dosage calculation for, 210

two-factor, 118, 194using drug label, 95

azactam, dosage calculation for, two-factor, 144 azithromycin (Zithromax), dosage calculation for, 213

B

batch number, of a drug, 78 Benadryl (diphenhydramine), dosage calculation for, three-factor, 205bipolar disorder, case study of, 246–247 bone marrow transplantation, case study of, 234bretylium tosylate, dosage calculation for, three-factor, 163 bronchopulmonary dysplasia, case study of, 243–244

Index

C

caplets, administration of, 84, 85fcapsules, administration of, 84, 85fCelsius temperature, 35

conversion to Fahrenheit, 37b, 36f, 40, 43ceptaz (ceftazidime), dosage calculation for, two-factor, 203cerebral palsy, case study of, 244chronic obstructive pulmonary disease (COPD), case study of, 230Cimetidine, 79, 86Cipro (Ciprofloxacin)

dosage calculation for, using drug label, 81drug label, components of, 79

cirrhosis, case study of, 236–237claforan, dosage calculation for

three-factor, 172two-factor, 122–123

cleocin, dosage calculation forone-factor, 190three-factor, 160, 205

clindamycin, dosage calculation for, three-factor, 172clinical depression, case study of, 248colestid (colestipol hydrochloride), dosage calculation for, two-factor, 198compazine (prochlorperazine), dosage calculation for

one-factor, 184, 187using drug label, 87, 92

congestive heart failure (CHF), case study of, 229–230conversion factors, in dimensional analysis, 48, 72 COPD (chronic obstructive pulmonary disease), case study of, 230cortef (hydrocortisone cypionate), dosage calculation for, two-factor, 197coumadin, administration of, 91cup, medication, 35b, 35f, 39t, 85fcystic fibrosis, case study of, 239, 240

D

decimals, 12–15converting between fractions and, 3, 16–17, 20dividing, 3, 15, 19, 21multiplying, 3, 14, 19, 21rounding, 13, 75

deep vein thrombosis, case study of, 233–234 demerol, dosage calculation for, 211denominator

in dimensional analysis, 48in fractions, 9

depo-Provera, dosage calculation for, one-factor, 192depression, case study of, 248diabetic ketoacidosis, case study of, 254–255digits, 6digoxin, dosage calculation for, 210

three-factor, 171two-factor, 193 dilantin

dosage calculation for, three-factor, 159IV therapy considerations, 132

dilaudid, dosage calculation for, 89, 212two-factor, 195

diluent, defined, 119dimensional analysis

defined, 48, 77, 158denominator in, 48

Note: Page locators followed by f and t indicates figure and table respectively.

LWBK732-Index_289-292:NEW.qxd 11/22/10 2:45 PM Page 289

dimensional analysis (contiuned)educational theory of, 287elements of, 48numerator in, 48one-factor, 72–78

defined, 72problem solving using, 72–78, 81–84, 85–108random method, 72, 77sequential method, 72, 73–74

random method, 72, 77sequential method, 72, 73–74solving problems with, 49–59

gallons to milliliters example, 51liter to ounces example, 49–50steps in, 48–49, 72

three-factor, 151–163 defined, 152, 158problem solving using, 152–173

two-factor, 115 defined, 115involving drop factors, 128–132involving intermittent infusion, 132–135 involving IV therapy, 124–128involving reconstitution, 119–124involving weight, 115–119 problem solving using, 136–144

dividing line, of fraction, 9division

of decimals, 3, 15, 19, 21 of fractions, 3, 11–12, 19, 21

dobutamine, dosage calculation for, three-factor, 155–156documentation, in medication administration, 69dopamine, dosage calculation for, 213

three-factor, 161–162, 164, 206–209dosage, in medication administration, 69 dram (dr), 34b, 34f, 39t drop factors

defined, 128medication problems involving, 128–132tubing considerations in, 128, 128t

drop (gtt), 35b, 35f, 39tdrug, see also under medication entries

in medication administration, 68–69drug label

components of, 78–80solving problems using, 81–84, 97–107

enteral, 84–90parenteral, 90–96

D5W solution, dosage calculation for, 211–212three-factor, 207 two-factor, 195

dysplasia, bronchopulmonary, case study of, 243–244

E

emphysema, case study of, 230end-stage renal failure, case study of, 255enteral medications, 84–90epivir (lamivudine), dosage calculation for, two-factor, 200–201 epoetin (Procrit), dosage calculation for, three-factor, 210epogen, dosage calculation for

three-factor, 170two-factor, 142

erythromycin dosage calculation forIV therapy, 133–134two-factor, 124

IV therapy considerations, 132 eskalith (lithium carbonate), dosage calculation for, one-factor, 192esmolol hydrochloride, dosage calculation for, three-factor, 210 expiration date, of a drug, 78, 79–80

F

Fahrenheit temperature, 35conversion to Celsius, 37b, 37f, 41, 43

fever of unknown origin (FUO), case study of, 251filgrastim, dosage calculation for, three-factor, 170fluid dram (fl dr), 34b, 34ffluid ounce (fl oz), 34b, 34f fluid volume deficit, case study of, 256

fortaz, dosage calculation for, two-factor, 124, 136, 196fractions, 9–12

components of, 9converting between decimals and, 3, 16–17, 20defined, 9dividing, 3, 11–12, 19, 21multiplying, 3, 9–11, 18, 21

fragmin, dosage calculation for, one-factor, 189furosemide, dosage calculation for

one-factor, 182three-factor, 158, 165, 204two-factor, 117, 141

G

gallon (gal)conversions, 34b, 34f, 39tdimensional analysis conversion, 51

gantrisin, dosage calculation for, two-factor, 203generic name, of a drug

defined, 78identification of, 68, 79–80

gentamicin, dosage calculation forthree-factor, 172, 205, 208two-factor, 115–117, 194, 197

given quantityin dimensional analysis, 48, 72in three-factor problem solving, 152in two-factor problem solving, 115.

glyset (miglitol), dosage calculation for, one-factor, 191grain (gr), 34b, 34f, 39t gram (g), 32, 32b, 32f, 39tgravity flow, IV therapy, 128–132

H

halcion (triazolam), 80dosage calculation for

one-factor, 181using drug label, 82

hemabate, dosage calculation for, one-factor, 188heparin

administration of, 91dosage calculation for, 211

IV therapy, 125, 127parenteral, 94, 96, 98two-factor, 136, 138–139

household measurement system, 33, 35b, 35fabbreviations, 32b, 35bimportance of, 33other system equivalents for, 39t

hydrea, dosage calculation for, three-factor, 206hydromorphone, dosage calculation for

one-factor, 186using drug label, 95, 106

hyperbilirubinemia, case study of, 245hypercholesterolemia, case study of, 252–253hyperemesis gravidarum, case study of, 237hypertension, case study of, 253–254hypoglycemia, signs and symptoms of, 90

I

increased intracranial pressure, case study of, 256–257infusion pump, 132. see also intermittent infusioninocor, dosage calculation for, three-factor, 162, 207insulin

administration of, 90dosage calculation for, 96, 98, 211using drug label, 93–94types of, 90

insulin syringe, 90, 90fintake and output, monitoring of, 35, 36f, 41, 43intermittent infusion, medication problems involving, 132–135intracranial pressure, increased, case study of, 256–257intravenous pumps, 124. see also intravenous therapy intravenous therapy

drop factors, 128–132gravity flow, 128intermittent infusion, 132–135types of tubing for, 128, 128t IV therapy, see intravenous therapy

2 9 0 INDEX


K

KCL. see potassium chloride (KCL)kilogram (kg), 33, 33b, 33f, 40

L

labor, premature, case study of, 238–239lactulose, dosage calculation for, 90, 104


leukemia, case study of, 241lidocaine, dosage calculation for, two-factor, 194lincocin (lincomycin), dosage calculation for, one-factor, 188lipids, dosage calculation for, 211liquid medication

cup administration, 85, 85fsyringe administration, 85, 85f

liter (L)conversions, 32, 33f, 33t, 39tdimensional analysis conversion, 49–50

lithium, dosage calculation for, one-factor, 192lot number, of a drug, 78lung cancer, small cell, case study of, 231

M

macrotubing, 128, 128tmagnesium sulfate, dosage calculation for


manufacturer, of a drug, 78measurement systems, 32–35

apothecaries’, 33–35household, 33, 35b, 35fmetric, 32–33for temperature, 35–36, 37ffor time, 36–37

medication administration, six rights of, 5, 68–69medication administration record (MAR), 70–71

defined, 70electronic, 70military time for, 36–37

medication cups, 35b, 35f, 39t, 85fmedication errors, prevention of, 68–69medication label, see drug label medication orders, interpretation of, 68–70medication problems

one-factor, 72–78defined, 73problem solving using, 73–78, 81–84, 86–107random method, 72sequential method, 72

three-factor, 151–163defined, 152, 158problem solving using, 152–173

two-factor, 115defined, 115involving drop factors, 128–132involving intermittent infusion, 132–135involving IV therapy, 124–128involving reconstitution, 119–124involving weight, 115–119problem solving using, 136–146

medication route, see also administration routesin medication administration, 69

meperidine, dosage calculation for, 96two-factor, 142using drug label, 86

meter, 32methylphenidate hydrochioride, dosage calculation for, using drug label, 83methylphenidate (Ritalin), dosage calculation for, using drug label, 100metric measurement system, 32–33

abbreviations, 32b, 40 defined, 32other system equivalents for, 39t, 40, 43volume in, 32, 33b, 33f, 39tweight in, 32, 32b, 32f, 39t

mezlin (mezlocillin), dosage calculation forIV therapy, 135two-factor, 120, 194, 197

microgram (meg), 32, 32b, 32f

micronase (glyburide), dosage calculation for one-factor, 191using drug label, 103

microtubing, 128military time, 36–37, 38f, 41, 45milligram (mg), 32, 32b, 32f, 39tmilliliter (mL)

conversions, 32, 33f, 33t, 39tdimensional analysis conversion, 50minim (M), 34b, 34f, 39t

mirapex (pramipexole), dosage calculation for, one-factor, 190morphine sulfate, dosage calculation for

one-factor, 180, 182three-factor, 169two-factor, 118, 144, 195using drug label, 92–93

multiplicationof decimals, 3, 14, 19, 21of fractions, 3, 9–11, 18, 21

mycostatin, dosage calculation for, 210

N

naloxone, dosage calculation forone-factor, 183using drug label, 107

neupogen, dosage calculation for, three-factor, 164nipride, dosage calculation for, 213

three-factor, 162–163, 165, 206–207nitroglycerin, dosage calculation for, two-factor, 195 normal saline, dosage calculation for, 209

IV therapy,, 129, 132two-factor, 203

NS. see normal salinenumbers

Arabic, 6Roman, 6, 6t

numeratorin dimensional analysis, 48in fractions, 9

O

one-factor medication problems, 72–78defined, 73problem solving using, 73–78, 81–84, 86–107random method, 72sequential method, 72

oral (PO) medications, 84–90orders, medication, interpretation of, 68–70orinase, dosage calculation for, using drug label, 97otitis media, case study of, 249–250ounce (oz)

conversions, 34b, 34f, 39tdimensional analysis conversion, 49–50

output, monitoring of, 35, 36f

P

pain management, case study of, 235–236parenteral medications, 90–96

routes for, 90syringes for, 90–91, 90f–91f

patient, in medication administration, 68persantine, dosage calculation for, using drug label, 98phenergan, dosage calculation for, two-factor, 118phenobarbital, dosage calculation for, 89

one-factor, 193pint (pt), 34b, 34f, 39tpipracil, dosage calculation for, 212pneumonia, case study of, 235potassium chloride (KCL), dosage calculation for, 212

two-factor, 195pound (Ib), 34b, 34f, 39tprednisolone, dosage calculation for, three-factor, 160prednisone, dosage calculation for

one-factor, 180, 185three-factor, 210

preeclampsia, case study of, 238 premature labor, case study of, 238–239procholorperazine, 87

INDEX 2 9 1


Q

quantitygiven

in dimensional analysis, 49, 75in three-factor problem solving, 162in two-factor problem solving, 120

wanted, in dimensional analysis, 49quart (qt), 34b, 34f, 40t

R

random method of dimensional analysisdefined, 72, 77problem solving using, 77

reconstitutiondefined, 124medication problems involving, 119, 124–129yield of, 124

renal failure, end-stage, case study of, 255respiratory syncytial virus (RSV), case study of, 240–241 rights, of medication administration, 5, 71–72Roman numeral system, 6, 6t

converting between Arabic and, 3, 6–9, 18, 21defined, 6

rounding, of decimals, 13, 78route, in medication administration, see administration routes

S

saline, dosage calculation for, 209IV therapy, 129, 132two-factor, 203

seizures, case study of, 250–251sepsis, case study of, 242–243sequential method of dimensional analysis

defined, 72problem solving using, 73–75

sickle cell anemia, case study of, 232–233small cell lung cancer, case study of, 231solu-Medrol, dosage calculation for

one-factor, 183three-factor, l73two-factor, 121–122using drug label, 107

spontaneous abortion, case study of, 245–246standard time, 36, 38f, 41, 45staphcillin, dosage calculation for, 212symbols, 6, 6tsyringes

insulin, 90, 90ffor insulin administration, 90, 90f3-mL, 90, 90ffor oral medication administration, 85, 85ffor parenteral medications, 90–91, 90f–91ftuberculin, 91, 91f

T

tablespoon (tbsp or T), 35b, 35f, 39ttablets, administration of, 84, 85ftagamet (cimetidine)

dosage calculation forthree-factor, 152–155, 164, 165, 204two-factor, 119, 199using drug label, 86–87, 105

drug label, components of, 79teaspoon (tsp or t), 35b, 35f, 39ttegretol (carbamazepine), dosage calculation for, using drug label, 88temperature, 35–36, 37f

Celsius, 35, 37fconversions, 37b, 37f, 41. 43Fahrenheit, 35, 37f

thorazine (chlorpromazine), dosage calculation for,two-factor, 199three-factor medication problems, 151–163defined, 152, 158problem solving using, 152–173

3-mL syringe, 90, 90fTigan (trimethobenzamide)

dosage calculation for, 97one-factor, 179, 185using drug label, 81–82, 84, 91, 105

drug label, components of, 81time, 36–37

considerations in IV therapy, 115conversions, 38f, 41, 45in medication administration, 69military, 36–37, 38fstandard, 36, 38f

titrationpurpose of, 151three-factor problem solving for, 151–152

Tolinase, dosage calculation for, using drug label, 83trade name, of a drug

defined, 78identification of, 68, 79–80

transplantation, bone marrow, case study of, 234transurethral resection of prostate (TURP), case study of, 252trimethobenzamide HCL, 81, 84tuberculin syringe, 91, 91ftylenol (acetaminophen), dosage calculation for, 76

one-factor, 180, 186two-factor, 136using drug label, 104

U

unasyn (ampicillin), dosage calculation for, 211, 213IV therapy, 134, 135three-factor, l73two-factor, 124, 136

unit path, in dimensional analysis, 48, 72

V

vancomycin, dosage calculation for, 211three-factor, 208two-factor, 137, 196

vantin, dosage calculation for, one-factor, 189venoglobulin, dosage calculation for, three-factor, 207verapamil, dosage calculation for, two-factor, 136vincasar (vincristine sulfate), dosage calculation for, two-factor, 198 vitamin Bi2, dosage calculation for, using drug label, 83volume

in apothecaries’ measurement system, 33, 34b, 34fconversion table, 39tin metric measurement system, 32, 33b, 33f

W

wanted quantity, in dimensional analysis, 48, 72warfarin, administration of, 91weight

in apothecaries’ measurement system, 33, 34b, 34fconversions, 39t, 116medication problems involving, 114–119in metric measurement system, 32, 32b, 32f

wellbutrin (bupropion hydrochloride), dosage calculation for, two-factor, 201

X

Xanax, dosage calculation for one-factor, 191using drug label,

Y

yield, of reconstitution, 119

Z

zantac, dosage calculation for, 89IV therapy, 135two-factor, 136, 202

zaroxolyn, dosage calculation for, 99zinacef (cefuroxime ), dosage calculation for, two-factor,202zofran (ondansetron hydrochloride), dosage calculation for, two-factor, 200zovirax (acyclovir), dosage calculation for, two-factor, 201

2 9 2 INDEX


TERMS USED IN DIMENSIONAL ANALYSIS

• Given quantity—the beginning point of the problem.• Wanted quantity—the answer to the problem. • Unit path—the series of conversions necessary to achieve the answer to the problem.• Conversion factors—equivalents necessary to convert between systems of measurement and allow unwanted units to

be canceled from the problem.

THE FIVE STEPS OF DIMENSIONAL ANALYSIS

1. Identify the given quantity in the problem.2. Identify the wanted quantity in the problem.3. Establish the unit path from the given quantity to the wanted quantity using equivalents as conversion factors.4. Set up the conversion factors to allow for cancellation of unwanted units.5. Multiply the numerators, multiply the denominators, and divide the product of the numerators by the product

of the denominators to provide the numerical value of the wanted quantity.

a– or a

ac

ad lib

AM

bid

c–

cap orcaps

cm

dr

DX

D5W

D5/1–2

NS

elix

et

fl or fld

g or gm

gal

gr

gtt

h or hr

IM

IV

IVPB

before

before meals

as desired, freely

in the morning, before noon

twice a day

with

capsule

centimeter

dram

diagnosis

dextrose 5% in water

dextrose 5% in water with 1–2normal saline

elixir

and

fluid

gram

gallon

grain

drop

hour

intramuscular(ly)

intravenous(ly)

intravenous piggyback

kg

KCl

KVO

L

Ib

liq

m

M or M

mcg

mEq

mg

min

mL

NPO

NS

os

oz

p–

p

PB

pc

per

po

PM

kilogram

potassium chloride

keep vein open

liter

pound

liquid

meter

minim

microgram

milliequivalent

milligram

minute

milliliter

nothing by mouth

normal saline, sodiumchloride or 0.9% NS

mouth

ounce

after

per

piggyback

after meals

by

by mouth, orally

afternoon or evening

as needed or whennecessary

pint

every hour

every 2 hours

every 3 hours

every 4 hours

every 6 hours

every 8 hours

four times a day

quart

rectal

rule out

treatment

without

subcutaneous(ly)

sublingual (beneath thetongue)

subcutaneous(ly)

immediately or at once

suppository

tablet

tablespoon

three times a day

to keep open

teaspoon

ABBREVIATIONS USED IN CLINICAL CALCULATIONS

prn

pt

qh

q2h

q3h

q4h

q6h

q8h

qid

qt

R

R/O

RX

s–

SC

SL

SQ

stat

supp

tab

tbs, tbsp, T

tid

TKO

tsp, t

LWBK732-Inside-Back-Cover:NEW.qxd 23/11/10 10:11 PM Page i

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