Eclampsia should be the presumed diagnosis in obstetric patients with seizures and/or coma without a known history of epilepsy. The incidence of eclampsia is between 1 in 2000 and 1 in 3500 pregnancies in developed countries. Eclampsia occurs in about 1% of patients with preeclampsia. Virtually, all eclampsia is preceded by preeclampsia.
The pathophysiology of eclamptic seizures is unknown but is related to arterial vasospasm and may occur when mean arterial pressure exceeds the capacity of cerebral autoregulation, leading to cerebral edema and increased intracranial pressure.
Eclampsia can occur antepartum, peripartum, or postpartum and has been reported as late as 3 to 4 weeks postpartum. Patients may have associated hypertension and proteinuria; a small percentage has neither.
Management of eclampsia is an obstetric emergency that requires immediate treatment, including
Appropriate management of ABCs (airway, breathing, and circulation) with measures taken to avoid aspiration
Seizure control with 6-g MgSO4 IV bolus. If the patient has a seizure during or after the loading dose, an additional 2-g IV bolus of MgSO4 can be given.
Treat seizures refractory to MgSO4 with IV phenytoin or a benzodiazepine (eg, lorazepam).
Treat status epilepticus with lorazepam 0.1 mg/kg IV at a rate ≥2 mg/min. Patients with status epilepticus may require intubation to correct hypoxia and acidosis and to maintain a secure airway.
Prevent maternal injury with padded bedrails and appropriate positioning.
Control of severe hypertension (see medications above)
Delivery is indicated after maternal stabilization.
During acute eclamptic episodes, fetal bradycardia is common. It usually resolves in 3 to 5 minutes. Allowing the fetus to recover in utero from the maternal seizure, hypoxia, and hypercarbia before delivery is optimal. However, if fetal bradycardia persists beyond 10 minutes, abruptio placentae should be suspected.
Emergency cesarean delivery should always be anticipated in case of rapid maternal or fetal deterioration.
Outcomes depend on the severity of disease. Perinatal mortality in the United States ranges from 5.6% to 11.8%, mainly due to extreme prematurity, placental abruption, and IUGR. The maternal mortality rate is from <1.8% in the developed world to 14% in under-resourced countries. Maternal complications include aspiration pneumonitis, hemorrhage, cardiac failure, intracranial hemorrhage, and transient or permanent retinal blindness.
Long-term neurologic sequelae of eclampsia are rare. Central nervous system imaging with computed tomography or magnetic resonance imaging should be performed if seizures are of late onset (longer than 48 h after delivery) or if neurologic deficits are clinically evident. The signs and symptoms of preeclampsia usually resolve within 1 to 2 weeks postpartum. Approximately 25% of eclamptic patients develop preeclampsia in subsequent pregnancies, with recurrence of eclampsia up to 2% of cases.