Pre Eclampsia 101105202758 Phpapp01

7/27/2019 Pre Eclampsia 101105202758 Phpapp01

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PRE-ECLAMPSIA


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Pre-Eclampsia

HYPERTENSION:Systolic BP > (or = to) 140 mmHgDiastolic BP > (or = to) 90 mmHg

confirmed by repeatedreadings over several hours

AND...


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Pre-Eclampsia

RENAL INVOLVMENT:Protein > 0.3g / 24 hoursDipstick > 1 +PCR > 30mg / mmol

OR...


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Pre-Eclampsia

MULTI-ORGAN COMPLICATIONS:Haemtological - Coagulopathy

- Haemolysis

Liver - Dysfuntion- Rupture of capsule

Neurological - Eclampsia- Stroke

Pulmonary OedemaFetal Growth RestrictionPlacental Abruption


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Hypertension in Pregnancy

There are four major types of high bloodpressure that may occur during pregnancy:

Pre-eclampsia

Chronic hypertension

Preeclampsia superimposed upon chronic

hypertension Gestational hypertension (also called

transient hypertension)


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Chronic Hypertension:

Chronic hypertension is defined as a bloodpressure 140/90 mmHg diagnosed either:

- Before pregnancy- Before the 20th week of pregnancy- Or that persists more than 12 weeks after

delivery.


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Pre-Eclampsia Superimposed Upon ChronicHypertension:

This refers to a woman with chronichypertension who develops signs of pre-eclampsia after the 20th week of pregnancy.


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Gestational Hypertension:

Women with gestational hypertension have all ofthe following:

- Blood pressure 140/90 mmHg

- No protein in the urine (proteinuria)

- Are 20 weeks pregnant

- No previous history of high blood pressure.


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Gestational Hypertension:

Over time, some pregnant women with gestationalhypertension will develop proteinuria and be

considered preeclamptic, while others will be

diagnosed with chronic hypertension because of

persistently high blood pressure after delivery.


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Pre-Disposing Factors

Age: 35 years

Ethnicity: Indian, Pacific

Obesity Diet: 130/80: Predisposing hypertension Miscarriage: 1 x lowers risk (immune response)

3 x increases risk (underlying)


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Pre-Disposing Factors

Partner: Relationship < 3 months, Fatherpreviously involved in pre-eclampticpregnancy

Woman born SGA

Family History: Pre-eclampsia, hypertension,diabetes, PCOS, underlying

thrombophilias Obstetric History: Previous pre-eclampsia,

donated gamate

Multiple Pregnancy


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Pathogenesis

NORMAL PREGNANCY:

Fetal trophoblast invade walls ofspiral arteries

This disrupts their smooth muscle layer andconverts them into venous-like channels

Remodelling begins about 5-6 weeks andcontinues until around 20-22 weeks

This allows blood supply to uterus to increasefrom 10-15 mls (pre-pregnancy) to 600-800 mlsper minute to meet placental blood flowrequirements at term


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Pathogenesis

In pre-eclampsia, this process is

DEFECTIVE

1. fewer of the arteries

undergoing these changes

2. changes may not extend throughout themyometrium of the spiral arteries


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PathophysiologyRenal

SYMPTOMS: Oliguria, Concentrated Urine

Proteinuria PCR > 30mg/mmol

Serum plasma creatinine > 90 umol/L

PATHOPHYSIOLOGY: Endothelial damage in glomeruli GFR impairedTubular necrosis and renal failure (rare)

EFFECTS: Reduced glomerular filtration rate, Reduced ureaclearance and increased uric acid concentration, Proteinuriaand hypoproteinaemia, Oliguria, Acute renal failure


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PathophysiologyLiver

SYMPTOMS: Epigastric/Upper back pain, malaise, flu-likesymptoms, nausea

Raised Serum Transaminases (AST & ALT most significant):Aspartate transaminase (AST) > 60 U/LAlanine transaminase (ALT) > 40 U/L

PATHOPHYSIOLOGY: Endothelial damage

Impaired

functionCapillary haemorrhage HaemotomaRuptured capsule

EFFECTS: Abnormal liver function tests, Subcapsularhaemorrhage and epigastric pain, Liver rupture


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PathophysiologyCardiovascular System

SYMPTOMS: Oedema

PATHOPHYSIOLOGY: Endothelial damage Altered

prostaglandin metabolism Increased thromboxane anddecreased prostacyclin concentration vasoconstriction

EFFECTS: Widespread vasoconstriction, Normal or

increased systemic vascular resistance, Left ventricularfailure, Increased vascular permeability and oedema,Decreased circulating blood volume


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PathophysiologyNeurological

SYMPTOMS: Severe headache, convulsions, persistantvisual disturbances

PATHOPHYSIOLOGY: Endothelial damage RetinopathyCerebral oedemaCVA (rare)

EFFECTS: Headaches, Visual disturbances, Hyper-reflexia,

Sustained clonus, Cerebral haemorrhage, Convulsions


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PathophysiologyHaematological

SYMPTOMS: Feeling hot/burning (unusual)

Thrombocytopenia Platelets


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PathophysiologyFetal Signs and Symptoms

SYMPTOMS: Slowed or slowing fetal growth, signs andsymptoms related to abruption and/or preterm labour

Abnormal biophysical profile scoreSlowed growth of the baby, based upon customised

growth chart and/or an ultrasound

Decreased amount of amniotic fluid around the baby, noted

on ultrasoundDecreased blood flow through the umbilical cord,

noted on Doppler tests


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PathophysiologyFetal Signs and Symptoms

PATHOPHYSIOLOGY: Reduced blood flow to the placenta

Decreased placental circulation Placental ischaemia

and infarction

EFFECTS: Intrauterine Growth Restriction, PlacentalAbruption, Preterm Labour


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Tests and Investigations

GPH Bloods:

Full / Complete Blood Count+Liver Group

+

Renal+Coagulation


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Tests and Investigations:Complete Blood Count

HAEMOGLOBIN [Hb]: 100 140 g/LThe iron-containing protein, which transportsoxygen within the red blood cells

In normal pregnancy, there is a natural decreasein Hb, due to haemodilation

In pre-eclampsia, expected plasma volumeincrease is impaired, affecting Hb estimation

If at 28/40 bloods, Hb is not lower than bookingbloods, this could be significant, and thereforeneed to be vigilant


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HAEMOGLOBIN [Hb]:

As the pregnancy progresses, and capillaries

become more damaged, they begin to leak,causing fluid to shift from the blood vessels toextravascular spaces

Blood therefore becomes more concentrated,and a raised Hb may indicate reduced plasma

(haemoconcentration) Plasma volume normal with mild disease, but

reduced with severe pre-eclampsia


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HAEMATOCRIT [PCV]: 0.28 0.41 (ratio)The proportion of total blood volume that isoccupied by erythrocytes

High PCV is suggestive ofhypovolaemia (lowvolume), which therefore may affect placental

perfusion No exact levels for Hb and PCV define significant

haemoconcentration,serial measurements aremore useful for monitoring the disease course


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PLATELETS: 150 400 109/LThe total number of thrombocytes, which playan integral role in haemostasis

Platelet levels decrease as they aggregatefollowing damage to the endothelial cells of the

capillaries Day-to day variations common so serial

measurements are necessary and moreinformative


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MEAN PLATELET VOLUME [MPV]: 6.4 9.7 flA measurement of the average size of platelets

The average lifespan of platelets is 5 9 days,and immature platelets are larger than matureones


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Tests and Investigations:Renal Function Investigations

SERUM UREA: 2.0 4.0 mmol/LAn organic chemical compound whichessentially is the waste produced when the bodymetabolizes protein

A late sign of renal injury as a result of

pre-eclampsia is impairment of glomerularfiltration which causes an increase in serum urea


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SERUM CREATININE: 0.04 0.08 mmol/LA breakdown product of creatine (muscle wastematerial), which is constantly produced andfiltered by the kidneys

Creatinine is removed from the body entirely by

the kidneys

Ifkidney function is abnormal, creatinine levelswill increase in the blood


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URATE (URIC ACID): 0.20 0.42 mmol/dEnd product of protein metabolism

Excreted by renal tubule, in preeclampsia thisfunction is impaired by damage to kidney andblood levels rise

High levels associated with poor fetal outcome

Useful diagnostic feature of early preeclampsia

Diet may affect level


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PROTEIN-CREATININE RATIO: 0 30 mg/mmol

Random (spot) urine protein-creatinine ratiocollected during normal daytime activity

Provides an accurate and rapid quantitation ofproteinuria in pregnant women with systemic

arterial hypertension and increased risk of pre-eclampsia


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CREATININE CLEARANCE: 120 160 ml/minThe volume of plasma completely cleared ofcreatinine per unit of time

Assesses the glomerular filtration rate

Gives an indication ofrenal function

Creatinine clearance may be reduced in pre-eclampsia as a result of decreased GFR

Assessed via 24 hour specimen


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Tests and Investigations:Liver Function Investigations

ASPARTATE TRANSAMINASE [AST]: < 45 U/LAn enzyme, involved in cellular metabolismthat has raised levels in acute liver damage

Also found in high concentrations in heart,muscle, kidney, pancreas and red blood cells

If any ofthese areas are damaged the bloodlevels of the enzyme will increase

Not specific for liver function


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ALKALINE PHOSPHATASE [ALP]: 90 - 250 U/LAn enzyme made in the liver, bone, and theplacenta, released into the blood during injury andduring such normal activities as bone growth andpregnancy

Involved in cell metabolism and present in nearly alltissues

Levels reach up to 3 times normal in pregnancy dueto placental phosphatase

Exaggerated increases may point to placental andhepatic damage in preeclampsia


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ALANINE TRANSAMINASE [ALT]: 7 - 45 U/LAn enzyme involved in cellular respiration, found inhighest amounts in the liver. It is released into the

blood through liver injury.

Found in low levels in other tissues

High levels are specific for hepatic damage

In normal pregnancy AST and ALTusually remain unchanged.

In severe preeclampsia they may be elevated


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GAMMA GLUTAMYL TRANSPEPTIDASE [GGT]: < 50 U/LAn enzyme that participates in the transfer of aminoacids across the cell membrane, and in glutathione (an

anti-oxidant) metabolism

Found almost entirely in the liver

Elevated in severe preeclampsia


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LACTATE DEHYDROGENASE [LDH]: 120 250 U/LAn enzyme that catalyzes the conversion oflactate to pyruvate

Found in liver, heart, skeletal muscle and redblood cells

As cells die, their LDH is released and finds itsway into the blood


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BILIRUBIN: 2 20 mmol/LBilirubin is a product that results from thebreakdown of hemoglobin

Serum bilirubin levels do not usually rise inpre-eclampsia, unless complicated by HELLP

syndrome


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SERUM ALBUMIN: 35 45 g/LAlbumin transports many small molecules in theblood (for example, bilirubin, calcium,

progesterone, and drugs). It is also of primeimportance keeping the fluid from the blood fromleaking out into the tissues.

Because albumin is made by the liver, decreasedserum albumin may result from liver disease

In pre-eclampsia low levels of albumin may also bethe result of protein lost through proteinuria


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Tests and Investigations:Coagulation

ACTIVATED PARTIAL THROMBOPLASTIN TIME [APTT]:35 - 45 secs

When you bleed, the body launches the coagulationcascade. There are three pathways to this event.

The APTT test looks at special proteins, calledfactors, found in two of these pathways (intrinsic).

A blood test that looks at how long it takes for

blood to clot It can help tell if there are bleeding or clotting

problems

A prolonged APTT time can be indicative of

disorders such as DIC, haemophilia, lupus, etc.


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Tests and Investigations:Coagulation

THROMBIN CLOTTING TIME: 10-18 secsA test which measures time required for plasmafibrinogen to form thrombin. Exogenous

thrombin is added to citrated plasma and thetime to clot formation is measured.

TCT is prolonged with abnormalities of

fibrinogen and in the presence of heparin or offibrin/fibrinogen degradation products

Prolonged in DIC as clotting mechanism fails


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Section 88 Maternity NoticeReferral Guidelines

Current Pregnancy - Pre-Eclampsia:

LEVEL 3 (Code 4022)- Blood Pressure >140/90 (or rise of >30/15)

AND...

- Proteinuria > 0.3g / 24 hours- Platelets < 150 x 109 / L- Abnormal renal or liver function- Imminent eclampsia / eclampsia


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Current Pregnancy - Eclampsia:

LEVEL 3 (Code 4006)


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Previous Obstetric History - Pre-Eclampsia:

LEVEL 1 (Code 3007)


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Previous Obstetric History - Pre-Eclampsia:

LEVEL 2 (Code 3008)WITH...- Significant IUGR- Requiring delivery


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CLASP TrialCollaborative Low-dose Aspirin Studies in Pregnancy

Aspirin and Calcium thought to producemodest reductions in blood pressure inpregnant women who are at above-average

risk for PE

Debate continues over gestation at whichprophylactic treatment should begin, but

earlier the better (approx. 6/40 gestation) Aspirin may also be beneficial in the

treatment of IUGR


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CLASP TrialCollaborative Low-dose Aspirin Studies in Pregnancy

For women who are at high risk of pre-eclampsia (>20%) Aspirin 100 mg daily

Calcium 1.5 g daily

For women who are at very high risk of pre-eclampsia or previous pregnancy had veryearly onset Heparin 7500 u BD or enoxaparin 40mg daily

Aspirin 100 mg daily


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Management

Depends on many factors:

Gestational age of the pregnancy

Severity of the disease Presence of complicating factors

Evidence of maternal compromise

Evidence of fetal compromise

The definitive treatment for pre-eclampsia is

delivery of the fetus and placenta


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Management

Expectant Management:

No evidence that hospital admission for mild PEimproves maternal or fetal outcomes

Admission to hospital is stressful, emotionally andfinancially costly

Women with mild PE without significantproteinuria may be treated as outpatient oradmitted as a day case for assessment andevaluation


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Management

Expectant Management:

Expectant management at home or hospital requires:

Reduced activity

Woman may be advised to stop working

May be advised to go on bed rest although this is logical

it has not been proved to improve outcomes

Careful recording and daily checking of:

Fetal activity

Blood pressure

Urine protein

Any other signs and symptoms of PE


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Management

Collaborative Management:

The goal is to:

Recognise pre-eclampsia early

Monitor the woman for evidence of diseaseprogression that would mandate either delivery

of more intensive fetal surveillance


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Management


Education for the family begins as soon as the diagnosis isconfirmed:

Should include information about the disease process

Signs and symptoms

Proposed course of treatment

Physical and laboratory investigations

Medications

Potential complications to mother and baby

Plan for birthing

Baseline laboratory evaluations:

Should be performed early in pregnancy for all women known to be

at high risk of PE


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Management

Collaborative Management: Blood pressure:

Should be recorded more frequently in women at high risk ofPE

Rapid increases warrant closer observation Fundal height:

Should be measured at each visit

A measurement less than expected may indicate IUGR oroligohydramnios

Presence of either IUGR or oligohydramnios may occurbefore any other diagnostic criteria for PE become apparent

Oedema: Rapidly increasing generalised, facial and/or periorbital

oedema requires further assessment


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Management


Once hypertension is documented in second half ofpregnancy, or onset of PE is suspected laboratory

investigations to track progression: Full blood count

Liver function tests

Renal tests

Coagulation screening

Urinanalysis


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Management

Collaborative Management: Fetal monitoring:

Antepartum surveillance (CTGs)

Symphyseal-fundal height measurements Record of fetal movements

Ultrasonography:

Amniotic fluid index

Fetal growth

Biophysical profiles Umbilical artery Doppler studies

Used to monitor fetal growth and to ascertain the mostappropriate and safest time for delivery


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Management

Hospital Management:

May be necessary for woman who:

Feel safer in hospital

Hypertension worsens Presence of significant proteinuria

Signs of end organ involvement

There are concerns about fetal wellbeing

Baseline laboratory evaluations as with Collaborativemanagement to monitor progression of disease

Crucial that an accurate fluid-balance chart maintained toensure that renal impairment detected early


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Management

Antihypertensive Therapy:

Indicated once the BP is persistently above

>160/100 mmHg, with the aim of achieving a

diastolic reading of 90 100 mmHg

This is to avoid overcorrection and the risk of

exacerbating placental hypoperfusion

Drugs used include methyldopa, atenolol andlabetalol

ACE inhibitors contraindicated in pregnancy


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Management

Timing of Delivery:

Delivery is the only cure for clinically diagnosed PE

Should be accomplished once the fetus is mature

Earlier if maternal condition deteriorates or if there isevidence of significant fetal compromise

Delivery should always take place in a level 2 hospital,where there are obstetric and paediatric facilitiesreadily available

Timing and management of delivery requires closecollaboration between the woman, midwifery,

obstetric, paediatric and anaesthetic teams


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Management

Timing of Delivery:

If fetus is between 24 -34 weeks gestation and urgentdelivery is required, corticosteroids are administered

to the mother Vaginal birth preferable

Epidural anaesthesia preferred choice of pain relief asthe maternal stress response releases catecholaminesand increases BP, although contraindicated if there isevidence of coagulopathy

Continuous monitoring of fetus

Syntometrine to be avoided for third stage due toergometrine component


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Management

Timing of Delivery:

Fetal indications for immediate delivery:

Intrauterine Growth Restriction

Non-reassuring CTG

Oligohydramnios

Maternal indications for immediate delivery:

Progressive deterioration of liver function Progressive deterioration of renal function

Suspected placental abruption

Persistent severe headache or visual changes

Persistent severe epigastric pain, nausea or vomiting


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Management

Management After Delivery:

30% of cases of PE only diagnosed in postpartumperiod

Following initial improvement, 60% of women willworsen within 48 hours of delivery

Antihypertensive drugs usually continued for afurther 48 hours

Close monitoring of BP should continue, as well as ameticulous fluid balance chart

Good analgesia cover to reduce maternal stress

Follow-up consultation and/or debrief


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Implications for Midwifery Care

Must begin with an accurate record of a womanshistory to identify risk factors and establishbaseline recordings of BP and laboratory values

Early recognition and diagnosis of physical signsrather than symptoms, as woman may feel well,yet have severe pre-eclampsia

Scope of care depends on severity of disease

Referral guidelines encompass a three-way

discussion between the woman, her midwife,and specialist therefore availability of themidwife paramount

Pre Eclampsia 101105202758 Phpapp01

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