Reproductive · Hypertensive Disorders of Pregnancy
The facts most likely to be tested
Eclampsia is defined as the occurrence of new-onset, generalized tonic-clonic seizures in a patient with preeclampsia that cannot be attributed to other neurological conditions.
Magnesium sulfate is the first-line pharmacologic agent for both the prevention and treatment of eclamptic seizures.
Delivery of the fetus is the only definitive treatment for eclampsia regardless of gestational age once the patient is stabilized.
Calcium gluconate is the specific antidote administered for magnesium toxicity, which manifests as loss of deep tendon reflexes, respiratory depression, and cardiac arrest.
Eclampsia typically presents with severe headache, visual disturbances (scotomata), and right upper quadrant or epigastric pain due to hepatic capsule distension.
Antihypertensive therapy with IV labetalol or IV hydralazine is indicated for acute management of severe-range blood pressures (≥160/110 mmHg) to prevent intracranial hemorrhage.
Eclampsia can occur in the antepartum, intrapartum, or postpartum period, with the majority of cases occurring within 48 hours of delivery.
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A 28-year-old G1P0 female at 36 weeks gestation presents to the labor and delivery unit after a witnessed generalized tonic-clonic seizure at home. Her prenatal course was notable for blood pressures of 150/95 mmHg and 155/98 mmHg at her last two visits, but she missed her follow-up. On examination, she is post-ictal, blood pressure is 170/110 mmHg, and 3+ proteinuria is noted on dipstick. Deep tendon reflexes are 2+ bilaterally.
What is the most appropriate next step in management?
Administer intravenous magnesium sulfate and initiate delivery.
The patient presents with eclampsia, necessitating immediate seizure prophylaxis with magnesium sulfate and definitive management via delivery of the fetus.
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Etiology / Epidemiology
Occurs in patients with preeclampsia; highest risk in nulliparous women and those with chronic hypertension.
Clinical Manifestations
New-onset tonic-clonic seizures in a pregnant patient; prodromal symptoms include severe headache and visual disturbances.
Diagnosis
Clinical diagnosis based on seizures in the setting of preeclampsia; no specific lab test confirms the seizure event.
Treatment
Magnesium sulfate is the first-line agent for seizure prophylaxis and termination; respiratory depression is the primary toxicity.
Prognosis
Requires immediate delivery regardless of gestational age; maternal mortality is significantly reduced by timely stabilization.
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Epidemiology & Etiology
Eclampsia is defined as the development of seizures in a patient with preeclampsia. Primary risk factors include nulliparity, multiple gestations, and pre-existing vascular disease. It is a life-threatening complication of the preeclampsia-eclampsia syndrome.
Pertinent Anatomy
The condition involves systemic endothelial dysfunction affecting the cerebral vasculature. Breakdown of the blood-brain barrier leads to vasogenic edema, primarily in the posterior cerebral regions.
Pathophysiology
Systemic endothelial dysfunction causes increased vascular permeability and hypertension. Cerebral autoregulation fails, resulting in hyperperfusion and cerebral edema. This triggers the seizure threshold to be exceeded, manifesting as generalized tonic-clonic activity.
Clinical Manifestations
Patients typically present with tonic-clonic seizures following a period of prodromal symptoms like epigastric pain, severe headache, and scotomata. Status epilepticus is a rare but critical emergency. Physical exam reveals hypertension and often hyperreflexia.
Diagnosis
Diagnosis is clinical; no gold standard imaging is required for the initial diagnosis. Labs typically show proteinuria (≥300 mg/24h or protein/creatinine ratio ≥0.3) and evidence of end-organ damage. Rule out other causes of seizures using non-contrast head CT if focal deficits persist.
Treatment
Administer Magnesium sulfate IV for seizure control. If seizures persist, use lorazepam or diazepam. Calcium gluconate is the antidote for magnesium toxicity. Control blood pressure with labetalol or hydralazine to prevent stroke. Delivery is the only definitive cure.
Prognosis
Maternal complications include placental abruption, pulmonary edema, and stroke. Continuous fetal heart rate monitoring is mandatory during the acute phase. Post-seizure stabilization is required before proceeding to cesarean section or induction.
Differential Diagnosis
Epilepsy: history of prior seizures
Cerebral venous thrombosis: focal neurologic deficits
Intracranial hemorrhage: sudden onset 'thunderclap' headache
Meningitis: nuchal rigidity and fever
Hypoglycemia: low serum glucose levels