What is the immediate treatment for a patient with eclampsia?

Immediate Treatment of Eclampsia

The immediate treatment for eclampsia requires administration of intravenous magnesium sulfate as the first-line anticonvulsant, along with antihypertensive therapy to maintain blood pressure below 160/105 mmHg, followed by delivery after maternal stabilization. 1, 2

Initial Management

Seizure Control

• Administer magnesium sulfate as the first-line anticonvulsant for seizure control and prevention of recurrence 1, 3
• Loading dose: 4-5g IV over 5 minutes, followed by maintenance dose of 1-2g/hour as continuous IV infusion for 24 hours after the last seizure 1, 3
• Alternative regimen: 4g IV loading dose followed by 10g IM (5g in each buttock), then 5g IM every 4 hours in alternating buttocks 2, 3
• Continue magnesium sulfate therapy until 24 hours after delivery or after the last seizure 1, 4

Blood Pressure Management

• Target blood pressure below 160/105 mmHg to prevent maternal complications 2, 1
• First-line IV antihypertensives include labetalol or nicardipine 2, 1
• Labetalol: Initial 20mg IV bolus, then 40mg after 10 minutes, followed by 80mg every 10 minutes to maximum 220mg 1
• Nicardipine: Start at 5mg/h, increased by 2.5mg/h every 5-15 minutes to maximum 15mg/h 1
• Avoid sodium nitroprusside due to risk of fetal cyanide toxicity 1
• Avoid diuretics as plasma volume is already reduced in preeclampsia 2, 1

Monitoring

Maternal Monitoring

• Continuous blood pressure monitoring 1
• Assess deep tendon reflexes before each dose - loss of patellar reflex occurs at plasma magnesium concentrations between 3.5-5 mmol/L and indicates impending toxicity 1, 4
• Monitor respiratory rate - respiratory depression occurs at 5-6.5 mmol/L 4
• Maintain urine output >100mL over 4 hours preceding each dose 1
• Laboratory tests: hemoglobin, platelet count, liver enzymes, creatinine, and uric acid 1

Fetal Monitoring

• Continuous fetal heart rate monitoring 1
• Ultrasound assessment of fetal biometry, amniotic fluid, and umbilical artery Doppler 1

Delivery Considerations

• Proceed with delivery after maternal stabilization 1
• Indications for immediate delivery include:
  • Inability to control blood pressure 2, 1
  • Progressive deterioration in liver function, creatinine, hemolysis, or platelet count 2, 1
  • Ongoing neurological features 2
  • Placental abruption 2
  • Abnormal fetal status 2, 1
  • Gestational age ≥37 weeks 1
• Vaginal delivery is preferred unless cesarean is indicated for obstetric reasons 1, 5
• For cesarean delivery, maintain left lateral positioning during the procedure to prevent aortocaval compression 5
• Regional anesthesia can be used only in conscious patients free from coagulopathy and HELLP syndrome 5
• General anesthesia may be necessary for sudden, unexpected interventions 5

Magnesium Sulfate Precautions

• Have injectable calcium salt available to counteract magnesium toxicity 1
• Avoid combination of magnesium sulfate with calcium channel blockers (like nifedipine) due to risk of severe hypotension 2, 1
• Signs of magnesium toxicity include:
  • Loss of patellar reflexes (early sign) 1, 4
  • Respiratory depression 1, 4
  • Cardiac conduction abnormalities (occurs at levels >7.5 mmol/L) 4
  • Cardiac arrest (occurs at levels >12.5 mmol/L) 4
• In severe renal insufficiency, maximum dosage should not exceed 20g/48 hours with frequent monitoring of serum magnesium levels 3

Post-Delivery Management

• Continue magnesium sulfate for 24 hours after delivery or last seizure 1
• Continue antihypertensive therapy during labor and postpartum period 1
• Check blood pressure and urine at 6 weeks postpartum 1
• Assess for secondary causes of hypertension in women under 40 with persistent hypertension 1

Common Pitfalls and Caveats

• Total daily dose of magnesium sulfate should not exceed 30-40g/24 hours 3
• Continuous use of magnesium sulfate in pregnancy beyond 5-7 days can cause fetal abnormalities 3
• Lower maintenance dose of magnesium sulfate (1g/hour vs 2g/hour) may be equally effective with fewer side effects 6
• Magnesium may reduce the antibiotic activity of streptomycin, tetracycline, and tobramycin when given together 3