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Toxicology Look‐A‐Likes:Poisonings Which Mimic 

Pediatric Illnesses

Angela C. Anderson, MD, FAAP

Case 1• A 2 year old presents with Vomiting, Fever,

and Kussmaul respirations.

• Urine Analysis - positive for glucose.• Serum glucose :

• HCO3: 10• pH 7.5, pC02 22

160

• What’s your diagnosis??

Toxic: 150 mg/kg

SalicylatesDiagnostic Delima

• 73 Consecutive ASA poisonings• 60% had neurologic or

psychiatric work-ups • Delay in Diagnosis 6 - 72 hours

• Anderson: Ann Intern Med, 1976(85):745

Salicylate Preparations

• Willow Bark

SalicylatesToxic Dose = 150 mg/kg

• Pepto-Bismol extra strength

• 10 kg Toddler–3 oz = toxic–9 oz = lethal–12 oz in bottle

Bismuth Subsalicylate

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• 1 Ounce ?• 21 Aspirin =

• 7,000 mg ASA

Oil of Wintergreen

• One tsp ?• 21 ASA 7000mg =• Death

Salicylate Pathophysiology

• Stimulates Medulla• Increases Metabolism• Promotes Bleeding

SalicylatesMechanisms of Toxicity

• Stimulation of Medulla

–Respiratory Alkalosis

Salicylates-Mechanisms of Toxicity

• Uncouple Oxidative Phosphorylation– Impaired O2 use

– Increased metabolism and lactic acid production• Increased heat production• [Glucose] Decreased or Increased• Metabolic Acidosis

Anion Gap Metabolic Acidosis [Na+ + K +] - [HCO3 -+ Cl -]> 10

• M - Methanol• U - Uremia• D - DKA• P - Paraldehyde• I - Iron• L - Lactic Acidosis• E - Ethylene Glycol• S - Salicylates

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SalicylatesMechanisms of Toxicity

• Decreased platelet aggregation• Decreased clotting factors• Increased capillary permeability

Cerebral edema Pulmonary edema

SalicylatesClinical Presentation

• Temp• HR• RR

– Kussmaul respirations– +/- Rales

• Tinnitus

SalicylatesClinical Presentation

• Vomiting• Agitation / MS / Szs. • Hyperventilation• Diaphoresis

What’s your diagnosis??..

• Vomiting, Kussmaul respirations, urine dip (+) for glucose = ?

• Fever, increased RR, rales = ?• Hyperventilating, anxious =?• Fever, vomiting, mental status change =?

Salicylate Intoxication

•Management

Activated Charcoal

• Prevent drug absorption

• Best if w/in 1 hour of ingestion

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SalicylateManagement –Prevent Absorption

• Whole Bowel Irrigation–GoLYTELY

•2L/hr adults•500cc/hr children

SalicylateManagement

Enhance Elimination

• Urine Alkalinization

• Hemodialysis

•Ionizes ASA

*

SalicylatesManagement

• Enhance Elimination–Urine Alkalinization

• 2 amps (100mEq) NaHCO3 +• D5W• Goal = pH >=7.5

–CHECK IT!!!

Salicylate - Final Tips

• Weird respiratory symptoms? • Weird fever?• Weird?• [pH = 7.5] + [HCO3 = 10] ?

Consider Salicylates !

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Case

• An agitated, terrified, 4 year old is rubbing briskly at her arms and legs and is screaming “get them off of me!”

On exam

• T 102.0• HR 150• RR 23• BP 100/60

• Skin -Flushed• Pupils -Dilated• Neck -supple• Heart -RRR• Lungs -CTA• Abd soft -NT• Extrem. -Warm & dry• Neuro –Agitated and

Hallucinating

Antihistamines / Anticholinergics Antihistamines / Anticholinergics

• Diphenhydramine• Hydroxyzine

• Cyclic Antidepressants• Antipsychotics

Cough and Cold Preps

• Brompheniramine• Chlorpheniramine

Jimson WeedAtropine, Scopolamine, Hyoscyamine

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Anticholinergics• Can’t urine• Can’t defecate• Can’t lacrimate• Can’t salivate…..

Atropine (Anticholinergic) Symptoms

Mad as a

Red as a

Dry as a

Hot as a

Blind as a

hatter

beet

bone

hare

bat

Antihistamines / Anticholinergics

Hot Dry

TachyWachy

AchSalivation

LacrimationUrinationDiarrhea

BronchorrheaBradycardia

Miosis

Muscarinic(Cholinergic)

Antihistamine

Ach

Muscarinic(Cholinergic)

AntihistamineDry Mouth

Urinary RetentionConstipationTachycardia

Dilated Pupils+/‐ Temp

Ach

CNS

Antihistamine

AnxietyHallucinations

SeizuresLethargy/Coma

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Dysrhythmias and QRS prolongation

Anticholinergics / Antihistamines

Antidote?

•Physostigmine

Ach

SalivationLacrimation

UrinationDiarrhea

BronchorrheaBradycardia

Miosis

Muscarinic(Cholinergic)

Ach-aseAntihistamine

Muscarinic(Cholinergic)

Ach-ase PhysostigmineAchAntihistamine

Ach

Muscarinic(Cholinergic)

Ach-ase Physostigmine

AchAntihistamineAch

Physostigmine

– Contraindicated if wide QRS

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Take Home Message…

Hot DryTachyWachy… ??...Think Antihistamines

Case 2

Seizure

• 8 month old

Case 28 month old w/ generalized Seizure

• T 38.9

• HR 180

• RR 40 

• Stiff neck

• WBC: 20K

• Na: 130

• CPK:1681 U/l• BP 125/70

• Pupils dilated 

CH3

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“Ecstasy”Why take it??

• Positive mood state

• Euphoria

• Closeness to others

• “ Love Drug “

PathophysiologyThe Serotonin System

MDMA stimulates Serotonin Release

AntidepressantAnxiolytic

Serotonin Re-uptake Transporter

Serotonin ExcessMDMA stimulates Serotonin Release

Consequences of excess serotonin receptor stimulation

• Serotonin Syndrome–Mental Status Change

–Autonomic Instability

–Neuromuscular Change

Consequences of Excess SerotoninMental Status Changes

• Anxiety

• Delirium

• Combativeness

• Mutism

• Coma

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Consequences of Excess SerotoninAutonomic Changes

• Tachypnea• Hypertension• Tachycardia

–Cardiac Dysrhythmias

–Cardiac Arrest • Diaphoresis / Fever

What it the highest temperature reported in an Ecstasy Exposure?

•A) 106 

•B) 108 

•C) 110

•D) 114

Consequences of Excess SerotoninNeuromuscular Changes

• Muscle rigidity / Tremors /    DTR’s /Clonus 

–Rhabdomyolysis

–DIC–Metabolic Acidosis

• Bruxism

But wait…there’s more….

• Intracranial hemorrhage

• Seizures

•Death

SerotonergicMigraine or Pain medications?

• Sumatriptan (Imitrex) • DHE

• Codeine• Meperidine• Tramadol Dextromethorphan Brompheniramine

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Herbal Remedies

• St. John’s Wart and Ginseng–Inhibits serotonin re-uptake

• L-tryptophan (“smart drink”)–Serotonin precursor

Illicit Drugs (Serotonergic)

• Cocaine• Amphetamines

• LSD • Ecstasy

How much is too much??

• Toxicity may be idiosyncratic !• Asymptomatic survival following 40 tablets

• Death reported from 2 tablets

Some Die,… Some Don’t 

• Historians unpredictable

• Composition unpredictable

• ? Ability to metabolize MDMA?

?

Serotonin Syndrome Treatment

• Discontinue the offending drug

• Supportive

• Benzo’s

• ? Cyproheptadine

Case 3

• A 6 yr old presents with vomiting and diarrhea

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Hopkinson JM, Pearce PJ, Oliver JS. BMJ 1980 Carbon Monoxide General Characteristics

• Colorless

• Odorless

• Tasteless

• Non‐irritating

• Very rapidly absorbed

Carbon MonoxideSources

•Natural

•Endogenous

•Exogenous• Methane + Oxygen CO + H20

C HH

HH

Carbon Monoxide Sources

Endogenous Production

• Hemoglobin Catabolism

–Normally                          COHgb < 1%

–Hemolysis          COHgb to 4 ‐ 8%

Carbon Monoxide ‐

Exogenous Sources

• Incomplete combustion of Carbonaceous materials:–Tobacco–Fuel–Coal–Wood

–Fibers

C CO CO2

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Carbon Monoxide Sources

• Tobacco Smoke

–1 pack/day              COHgb = 5‐6%

–Passive inhalation

2.5 Xx

Fires

• CO levels may reach 10%

• COHgb levels to 75% in 1 min. –w/out respiratory

protection

Automobile Exhaust

• Increased cardiovascular deaths

Catalytic converter9% CO 1% CO

•Lethal CO levels in a closed garage in 10 min.

Automobile Exhaust

Carbon Monoxide Sources

• Zamboni

Absorption of Carbon Monoxide

Rate determined by:

–1)  Minute ventilation       &

– 2) Cardiac output

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Neonates and Children

MMWR April 23, 2003

No Catalytic Convertersbefore 2008/2010

Hgb

CO

O2

O2

Cardiac and Skeletal Myoglobin

3 : 1

Carbon Monoxide

NO

PMN’s

Hypotension

Plts.

Endothelium

Cerebral Lipid Peroxidation

CO-HgbCO

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Carbon MonoxideMost Susceptible Organs

• Highest O2 requirements

MyocardiumBrain

Cardiac Presentations of CO

• Chest Pain

• Irritability

• Syncope

• Death

CNS Manifestations of Acute CO Exposure

• Headache

• Vomiting

• Lethargy

• Dizziness

• Syncope

• Irritability

• Seizures

• Coma

Delayed Neuropsychiatric Sequelae

• Symptom free period of up to 6 weeks 

• Reported in up to 40% of CO exposed patients

• Classically follows period of LOC from prolonged exposure

Delayed Neuropsychiatric Sequelaein Children

• Memory Impairment–Occurs in up to 43%

• Affective Incontinence– Emotional Lability

– Secondary to Hippocampal Damage

• Visuospatial Disorders– Secondary to Parietal Damage

Delayed Neuropsychiatric Sequelae

•50% recover

–May take 1 year

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Management of CO Intoxication

•ABC’s

•100% Oxygen

COT 1/2 Elimination

Room Air 5-6 hours

100% Oxygen 1 hour

HBO (3atm) 20-30 minutes

Hyperbaric Oxygen

•O2 given at 2 ‐ 3X atmospheric pressure 

•PaO2 = 2000 torr

Hyperbaric Oxygen

• CO‐Hgb elimination

• O2 dissolved in plasma

• Neurologic sequelae

–Decreases lipid peroxidation

–Decreases neutrophil adherence

Follow‐up Testing

• Ophthalmologic

• Hearing 

• Neuropsychiatric

Prevention and Safety

Replace q 5 to 7 yrs

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Take Home Points

• No Domino effect– Everyone got sick at the same time

• Improvement with change of environment

• History of Car or Boat travel

• Sports