Eclampsia


DEFINITION
Eclampsia is the occurrence of seizures or coma in a woman with preeclampsia, occurring at .20 wk of gestation or ,48 hr postpartum. Atypical eclampsia occurs at ,20 wk of gestation or as much as 14 days postpartum.

SYMPTOMS

Toxemia
Seizures of pregnancy

EPIDEMIOLOGY

INCIDENCE: One case per 150 to 3000 pregnancies; 2% to 4% of those with preeclampsia
GENETICS: Increased incidence with a firstdegree relative (sister or mother) having had eclampsia
RISK FACTORS: Multifetal gestation (3.6% in twin gestation), molar pregnancy, nonimmune hydrops fetalis, uncontrolled hypertension, preexisting hypertension, renal disease

PHYSICAL FINDINGS

PHYSICAL FINDINGS & CLINICAL PRESENTATION
 -  Seizure begins as facial twitching, then spreads to generalized clonicotonic state, with cessation of respiration followed by a postictal period of amnesia, agitation, and confusion.
 -  40% have severe hypertension, 40% have mild to moderate hypertension, and 20% are normotensive.
 -  Generalized edema with rapid weight gain (.2 lb/wk) may be one of the earliest signs of eclampsia.
 -  Persistent occipital headache and hyperreflexia with clonus occur in 80% of patients with eclampsia; epigastric pain occurs in 20% of these patients.


ETIOLOGY

 -  Exact etiology unknown.
 -  Common pathway relates to abnormalities in autoregulation of cerebral blood flow. This may involve transient vasospasm, ischemia, cerebral hemorrhage, and edema occurring by a mechanism involving hypertensive encephalopathy, decreased colloid osmotic pressure, and prostaglandin imbalance.


DDx

DIFFERENTIAL DIAGNOSIS
 -  Preexisting seizure disorder
 -  Metabolic abnormalities (hypoglycemia, hyponatremia, hypocalcemia)
 -  Substance abuse
 -  Head trauma, infection (meningitis, encephalitis)
 -  Intracerebral bleeding or thrombosis
 -  Amniotic fluid embolism
 -  Space-occupying brain lesions or neoplasms
 -  Pseudoseizure

WORKUP

 -  Rule out other causes of seizures during pregnancy.
 -  Atypical presentations such as prolonged postictal state; status epilepticus; gestational age ,20 wk or .48 hr postpartum; or signs of meningitis, substance abuse, or severe uncontrolled hypertension should prompt a search for other seizure etiologies.

LABORATORY TESTS
 -  Proteinuria: severe (49%), mild to moderate (29%), absent (22%)
 -  Hct: elevated as a result of hemoconcentration
 -  Platelet count: decreased; LFTs elevated in HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count)
 -  BUN and creatinine: elevated with renal involvement
 -  Serum electrolytes, glucose, calcium, toxicology profile: rule out other causes of seizures
 -  Hyperuricemia: > 6.9 mg/dl found in 70% of eclamptics
 -  ABG: maternal acidemia and hypoxia

IMAGING STUDIES
 -  CT scan or MRI indicated in atypical presentation, suspected intracerebral bleeding, or focal neurologic deficit.
 -  There are abnormal findings, including cerebral edema, hemorrhage, and infarction, in 50% of patients.


TREATMENT

NONPHARMACOLOGIC THERAPY
 -  Airway protection (risk of aspiration)
 -  Supportive care during acute event

ACUTE GENERAL Rx
 -  Maintain airway, adequate oxygenation, and IV access.
 -  Fetal resuscitation, involving maternal O2, left lateral positioning, and continuous fetal heart rate monitoring, is needed.
 -  Magnesium sulfate is the drug of choice.

  • Give Magnesium sulfate 6 g IV load over 20 min, then 3 g/hr maintenance, for recurrent seizure prophylaxis.
  • If repeated convulsions, may give an additional 2 g IV over 3 to 5 min. Approximately 10% to 15% of patients will have a second seizure after initial loading dose.
  • Check Magnesium level 1 hr after loading dose, then q6h (therapeutic range 4 to 6 mg/dl).
  • Antidote for toxicity: Calcium gluconate 10 ml of 10% solution.
  • Phenytoin has been used as an alternative in patients in whom magnesium sulfate is contraindicated (renal insufficiency, heart block, myasthenia gravis, hypoparathyroidism).
     -  Give Sodium amobarbital 250 mg IV over 3 min for persistent seizures.
     -  Treat blood pressure if  >160 mm Hg/110 mm Hg with
    • Labetalol 20- to 40-mg IV bolus,
    • Hydralazine 10 mg IV, or
    • Nifedipine 10 to 20 mg sublingual q20min.
  • Evaluate patient for delivery.

CHRONIC Rx
 -  The first priority is stabilization of the mother in terms of adequate Oxygenation, hemodynamics, and laboratory abnormalities, such as associated coagulopathies.
 -  Cervical status and gestational age should be assessed. If unfavorable cervix and < 30 wk of gestation, consider C-section; otherwise consider induction.
 -  Controlled epidural is the anesthesia of choice for labor or C-section.
 -  Avoid general anesthesia in uncontrolled hypertension to minimize risk of catastrophic cerebral events.

DISPOSITION

The maternal mortality rate for eclampsia averages 5% to 6%. Morbidity rate is 25%, including placental abruption (10%), maternal apnea with fetal asphyxia, aspiration pneumonia, pulmonary edema (4%), renal failure, cardiopulmonary arrest, and coma.

REFERRAL

Because of the potential for serious permanent maternal and fetal sequelae, all cases should be managed by a team approach of obstetrician, neonatologist, and intensivist.

PEARLS & CONSIDERATION

 -  Eclampsia: antepartum, 50%; intrapartum, 20%; and postpartum, 30%.
 -  Postseizure there is an associated period of fetal bradycardia from 1 to 9 min; if there is evidence of fetal compromise beyond that time, consider alternative etiologies such as placental abruption (23% incidence).