PREECLAMPSIA

Reinaldo Figueroa, MD

Winthrop-University Hospital

PREECLAMPSIA

• Hypertensive disorder specific to pregnancy– affects nearly 6% of all pregnancies– a major cause of maternal and neonatal

mortality and morbidity– 15 to 20 % of maternal mortality in developed

countries

PREECLAMPSIA

• Severity ranges from:– a mild disorder (transient hypertension in the

later part of the pregnancy) to– a life-threatening disorder with seizures,

HELLP syndrome, fetal hypoxia, and growth retardation

• more severe disease: 0.56 per 1000 deliveries

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• Predisposes women to other serious complications:– placental abruption– acute renal failure– cerebral hemorrhage– disseminated intravascular coagulation– circulatory collapse

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• The etiology is unknown

• believed to be involved:– immune maladaptation– placental ischemia– oxidative stress– genetic susceptibility

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• Classification of hypertension in pregnancy– Gestational hypertension– Preeclampsia / eclampsia– Chronic hypertension– Preeclampsia superimposed on chronic

hypertension

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• Definition of hypertension– a systolic blood pressure of 140 mmHg or above,– or a diastolic blood pressure of 90mmHg or

above,– on two occasions 6 hours apart

• Abnormal proteinuria– the excretion of 300 mg or more of protein in 24

hours

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• Criteria for severe preeclampsia– Blood pressure: > 160 mmHg systolic or >

110 mm Hg diastolic– Proteinuria: > 5 g in 24 hours– Persistent and severe cerebral or visual

disturbances (headache, scotoma, blurred vision)– Persistent and severe epigastric pain or right

upper quadrant pain

PREECLAMPSIA

• Criteria for severe preeclampsia– Pulmonary edema or cyanosis– Oliguria (< 500 mL of urine in 24 hours)– Eclampsia (grand mal seizures)– HELLP syndrome

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• Screening tests for gestational hypertension• routine components of antepartum care trimester• early detection of vasoconstriction• early detection of altered renal function• early detection of altered hemodynamics• detection of placental hypoperfusion / ischemia• detection of endothelial activation or injury• detection of an activated coagulation / fibrinolytic

system

PREECLAMPSIA

• Prevention of preeclampsia• women at risk: multifetal gestation, vascular or renal

disease, previous severe preeclampsia-eclampsia, abnormal uterine artery Doppler velocimetry

• antihypertensive drugs

• magnesium

• zinc

• fish oil

• calcium

• low-dose aspirin

PREECLAMPSIA

• Mild preeclampsia - management– < 37 weeks gestation

• inpatient or outpatient management

• worsening disease: delivery, magnesium sulfate

– > 40 weeks gestation• delivery, magnesium sulfate

– 37 - 39 weeks gestation• inducible cervix: delivery, magnesium sulfate

• cervix not inducible: inpatient or outpatient management

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• Severe preeclampsia - expectant management– gestational age: not recommended for < 24

weeks or > 34 weeks gestation– hospitalization: tertiary care center– antenatal testing: daily

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• Severe preeclampsia - guidelines for expedient delivery– maternal indications

• eclampsia, thrombocytopenia, pulmonary edema, acute renal failure

• persistent severe headache or visual changes

• elevated liver enzymes with persistent severe epigastric pain or right upper quadrant tenderness

• labor or rupture of membranes

• vaginal bleeding, abruptio placenta

PREECLAMPSIA

• Severe preeclampsia - guidelines for expedient delivery– fetal indications

• repetitive severe variables or late decelerations

• biophysical profile < 4 on two occasions 4 hours apart

• amniotic fluid index < 2 cm

• intrauterine growth restriction

• fetal death

• > 34 weeks gestation

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• Severe preeclampsia - management protocol– admission to labor and delivery for 24 hours– magnesium sulfate IV for 24 hours– antihypertensives if diastolic blood pressure

> 110 mmHg– meet guidelines for expedited delivery?

• yes? delivery

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• Severe preeclampsia - management protocol– Expedited delivery? no?

• < 23 weeks: counseling for termination of pregnancy• 23-32 weeks: steroids, antihypertensive medications,

daily maternal and fetal evaluation, delivery at 34 weeks

• 32-33 weeks: amniocentesis– immature fluid - steroids, delivery in 48 hours

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• HELLP syndrome - diagnosis– 10% before 27 weeks– 20% after 37 weeks– 70% between 27 and 37 weeks– slow initial phase with accelerated final phase

versus secondary expression of sepsis, ARDS, renal failure

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• HELLP syndrome– parameters used to diagnose preeclampsia are

not reflective of disease severity– target organ systems

• liver

• brain

• kidneys

• coagulation system

– increased maternal and perinatal risk

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• HELLP syndrome - diagnostic criteria– hemolysis

• abnormal peripheral smear

• lactate dehydrogenase > 600 U/L

– elevated liver enzymes• serum aspartate aminotransferase > 70 U/L

• lactate dehydrogenase > 600 U/L

– low platelets• platelet count < 100,000/mm3

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• HELLP syndrome - differential diagnosis– acute fatty liver of pregnancy– appendicitis– diabetes insipidus– gallbladder disease– gastroenteritis– glomerulonephritis– hemolytic uremic syndrome– hepatic encephalopathy

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• HELLP syndrome - differential diagnosis– idiopathic thrombocytopenia– kidney stones– pancreatitis– pyelonephritis– systemic lupus erythematosus– thrombotic thrombocytopenia purpura– viral hepatitis

PREECLAMPSIA

• HELLP syndrome - antepartum management• assess and stabilize the maternal condition• correct coagulopathy if DIC is present• give intravenous magnesium sulfate to prevent seizures• provide treatment for severe hypertension to prevent

stroke• transfer to tertiary center if appropriate• if subcapsular hematoma of liver, computed tomography

or ultrasound of the abdomen

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• HELLP syndrome - antepartum management– evaluate fetal well-being

• non stress test

• biophysical profile

– timing of delivery• if > 34 weeks gestation, deliver

• if < 34 weeks gestation, administer corticosteroids, then deliver in 48 hours

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• HELLP syndrome - management for cesarean birth– use general anesthesia if platelet count is

< 75,000 / mm3

– transfuse 5 to 10 units of platelets before surgery if platelet count is < 50,000 / mm3

– leave vesicouterine peritoneum open– install subfascial drain

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• HELLP syndrome - management for cesarean birth– schedule secondary closure of skin incision or

subcutaneous drain

– administer postoperative transfusions as needed

– perform intensive monitoring for at least 48 hours postpartum

– consider dexamethasone (10 mg IV every 12 hours) until postpartum resolution of disease occurs

PREECLAMPSIA

• HELLP syndrome - management of women with a subcapsular liver hematoma– general considerations - blood bank aware for

potential need of many units of blood– general or vascular surgeon consultation– avoid direct and indirect manipulation of liver– closely monitor hemodynamic status– management of hematoma depends on whether it is

ruptured or not

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• Eclampsia– occurrence of convulsions or coma unrelated to

other associated conditions– all new onset seizures during pregnancy -

eclampsia until proven otherwise– incidence: 1 in 500 pregnancies

• 3% in multiple gestations

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• Eclampsia– precise cause unknown– theories

• vasospasm

• ischemia

• edema

• multisystem organ failure

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• Eclampsia– seizures usually occur without aura– hypertension not severe in 20% – edema absent in 30%– proteinuria absent in 20%– hyperreflexia is not predictive of seizure– headache or visual changes - most common

precipitating event

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• Eclampsia– 80% of convulsions occur before or during the

delivery– 1/3 of cases may be not preventable– atypical

• less than 20 weeks gestation

• more than 48 hours postpartum

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• Eclampsia - risk factors– low socioeconomic status– extremes in childbearing age– African-American– no prenatal care– substance abuse

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• Eclampsia - management– control convulsions– correction of hypoxia and acidosis– blood pressure control– delivery after maternal stabilization

PREECLAMPSIA

• Eclampsia - anticonvulsant therapy– magnesium sulfate

• mechanism of action - smooth muscle relaxation by displacement of calcium

• dosage - 4-6 g intravenous loading dose, followed by 2 g per hour

• may be given intramuscularly

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• Eclampsia - magnesium sulfate– side effects:

• maternal hypotonia

• respiratory depression

• cardiac arrest

• neonatal depression

– contraindicated in myasthenia gravis– use with caution in renal insufficiency

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• Eclampsia - anticonvulsant therapy– phenytoin

• used extensively in Europe

• may be used in myasthenia gravis

• mechanism of action - may increase gamma aminobutyric acid-mediated chloride conduction in postsynaptic membranes

• may inhibit neurotransmitter inhibitory systems

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• Eclampsia - phenytoin– dosage - 1 g loading dose over 1 hour– cardiac monitoring during administration– side effects

• arrhythmias with rapid administration

• hepatitis

• Steven-Johnson syndrome

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• Eclampsia - anticonvulsant therapy– diazepam

• useful for status seizures

• mechanism of action - facilitate the binding of GABA to its receptor

– benzodiazepine receptors

• dosage - 10 mg at a rate of 5 mg per min

• may be repeated at 10 to 15 minute intervals

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• Eclampsia - diazepam– side effects - loss of consciousness, hypotension,

respiratory depression– caution - may increase risk of aspiration– causes prolonged depression of the neonate

• sodium thiopentotal– long acting barbiturate– used when sedation, paralysis and intubation needed

PREECLAMPSIA

• Eclampsia - which anticonvulsant to use?– magnesium is associated with decreased

recurrence risks of seizures when compared with diazepam or phenytoin

– diazepam is associated with increased need for mechanical ventilation

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• Eclampsia - management of fetus– fetal bradycardia during seizure

• ~ 5 minutes after the onset of the seizure

• may be associated with rebound tachycardia

• recovery phase may show late decelerations

– monitor for uterine hypertonicity• allow for fetal recovery

• monitor for signs of abruption

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• Eclampsia– delivery is indicated regardless of gestational

age– immediate cesarean delivery is not necessary

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• Eclampsia - radiographic evaluation– should be reserved for women with

neurological deficit, recurrent seizures, or atypical presentation

– abnormal CT findings - 50%• edema, hemorrhage, infarction

– cerebral angiography has limited use– 90% of EEG evaluations may be abnormal

PREECLAMPSIA

• Eclampsia - management• allow patient to have seizure

• use bite block as needed to prevent maternal injury

• establish airway

• administer magnesium sulfate as soon as possible

• obtain arterial blood gases

• monitor urine output

• control hypertension

PREECLAMPSIA

• Eclampsia - management– rebolus with magnesium sulfate if repeat

seizure occurs– do not intervene for fetal status while mother is

unstable– if seizure continues, paralyze and intubate.

PREECLAMPSIA

• Counseling regarding future pregnancies - HELLP syndrome – information available varies– recurrent risk of preeclampsia: 43% (19%)– recurrent risk of HELLP syndrome: 19-27%

(3%)– If HELLP syndrome < 32 weeks

• recurrent risk of preeclampsia / eclampsia is 61%

THANK YOU

• Sibai BM. Hypertensive disorders in women. 2001.

• Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998;92:883-9.

• Sibai BM. Diagnosis and management of gestational hypertension and preeclampsia. Obstet Gynecol 2003;102:181-92.

• Sibai BM. Diagnosis, prevention, and management of eclampsia. Obstet Gynecol 2005;105:402-10.