What is the management approach for a pregnant woman with eclampsia?

Management of Eclampsia

Magnesium sulfate is the definitive first-line treatment for eclamptic seizures and must be administered immediately, followed by urgent blood pressure control with oral nifedipine or IV labetalol, with delivery being the definitive treatment after maternal stabilization. 1

Immediate Seizure Management

Administer magnesium sulfate immediately as the anticonvulsant of choice for eclamptic seizures. 1

• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 2
• Maintenance infusion: 1-2 g/hour continuous IV 1, 2
• Alternative regimen: 4 g IV bolus followed by 5 g IM in each buttock (10 g total), then 4-5 g IM into alternate buttocks every 4 hours as needed 2

Magnesium sulfate reduces recurrent seizures by 66% compared to phenytoin (RR 0.34,95% CI 0.24-0.49) and is superior to all other anticonvulsants. 3 Phenytoin should be abandoned for eclampsia management. 3

Supportive Care During Seizure

• Position patient on left side to prevent aspiration and maintain airway patency 4
• Ensure airway, breathing, and circulation are maintained 4
• Protect patient from injury during convulsions 4
• Administer supplemental oxygen 4

Monitoring for Magnesium Toxicity

• Monitor deep tendon reflexes (loss of patellar reflex indicates toxicity) 2
• Monitor respiratory rate (respiratory depression occurs at toxic levels) 2
• Target therapeutic serum magnesium level: 6 mg/100 mL (4.8-8.4 mg/dL) 2
• Critical warning: Maximum total daily dose should not exceed 30-40 g in 24 hours 2
• In severe renal insufficiency, maximum dose is 20 g/48 hours with frequent serum magnesium monitoring 2
• Antidote: Calcium gluconate 1 g IV for respiratory arrest from magnesium toxicity 5

Urgent Blood Pressure Control

Initiate antihypertensive therapy immediately if BP ≥160/110 mmHg persists for >15 minutes to prevent maternal cerebral hemorrhage. 1

First-Line Antihypertensive Options

• Oral nifedipine (preferred): Most effective first-line agent 1
• IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg) 6
• IV hydralazine: 5-10 mg IV every 20 minutes as needed (note: associated with more perinatal adverse effects than other agents) 7

Blood Pressure Targets

• Target systolic BP: 110-140 mmHg 1, 6
• Target diastolic BP: 85 mmHg 1, 6
• Minimum acceptable: <160/105 mmHg 6

Comprehensive Laboratory Assessment

Obtain immediately to assess for complications and guide management: 1

• Complete blood count with hemoglobin and platelet count (assess for thrombocytopenia <100,000/μL) 1
• Comprehensive metabolic panel including AST/ALT, creatinine, and uric acid (evaluate for HELLP syndrome and renal dysfunction) 1
• Coagulation studies if platelets <100,000/μL or clinical bleeding 4

Maternal Monitoring Protocol

• Blood pressure: Continuous monitoring or every 4 hours while awake 1, 6
• Neurological assessment: Monitor for visual disturbances, severe headache, epigastric or right upper quadrant pain 1
• Respiratory monitoring: Assess for pulmonary edema (rales, oxygen saturation <90%) 1
• Fluid management: Restrict to 60-80 mL/hour to avoid pulmonary edema, target urine output 0.5-1 mL/kg/hour 1

Fetal Assessment

• Electronic fetal heart rate monitoring to assess fetal well-being 1
• Non-reassuring fetal status is an absolute indication for immediate delivery 1

Delivery Planning

Delivery is the definitive treatment for eclampsia and should occur after maternal stabilization. 1

Timing of Delivery

• ≥37 weeks gestation: Deliver immediately after maternal stabilization 1, 6
• 34-37 weeks: Deliver after maternal stabilization 6
• <34 weeks: Deliver immediately if any of the following absolute indications are present 1, 6:
  • Inability to control BP despite ≥3 classes of antihypertensives
  • Placental abruption
  • Non-reassuring fetal status
  • Maternal oxygen saturation deterioration (<90%)
  • Progressive thrombocytopenia
  • Pulmonary edema
  • Severe intractable headache or repeated visual scotomata

Mode of Delivery

• Neuraxial anesthesia is preferred for cesarean section in conscious, seizure-free women with stable vital signs 4
• Vaginal delivery is acceptable if obstetric conditions are favorable 8

Postpartum Management

Continue magnesium sulfate for 24 hours postpartum, as eclampsia can occur in the postpartum period (recurrence rate 0.6% with magnesium vs 2% without). 1

• Monitor BP at least every 4-6 hours for at least 3 days postpartum 1
• Continue neurological monitoring, as postpartum eclampsia remains a risk (11-44% of eclampsia occurs postpartum, with increasing proportion occurring >48 hours after delivery) 1, 8
• Repeat laboratory tests (hemoglobin, platelets, creatinine, liver enzymes) the day after delivery and then every other day until stable 1
• Avoid NSAIDs for postpartum analgesia, especially with renal dysfunction, as they worsen hypertension and renal function 1, 6

Critical Pitfalls to Avoid

• Do not underestimate disease severity: All eclampsia can rapidly progress to life-threatening complications including placental abruption, DIC, pulmonary edema, aspiration pneumonia, cardiopulmonary arrest, and acute renal failure 1, 9
• Do not rely on blood pressure alone: Serious organ dysfunction develops at relatively mild BP elevations 1, 6
• Do not delay magnesium sulfate: Eclamptic seizures occur in 2% of women with severe preeclampsia not receiving magnesium sulfate vs <0.6% in those receiving it 9
• Do not use continuous magnesium sulfate beyond 5-7 days in pregnancy: This can cause fetal abnormalities 2
• Do not use diuretics routinely: They further reduce plasma volume which is already contracted in preeclampsia 6

Special Considerations for HELLP Syndrome

• HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) carries 3.4% maternal mortality 1, 6
• Epigastric or right upper quadrant pain is the hallmark symptom 1
• Monitor glucose intraoperatively as severe hypoglycemia can occur 6
• Manage as severe preeclampsia with all features addressed 6

Long-Term Implications

• Women with eclampsia have 1-2% recurrence risk and 22-35% risk of preeclampsia in subsequent pregnancies 8
• Eclampsia is associated with long-term cardiovascular risk and potential cognitive difficulties related to memory and concentration 9
• Review at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 6