What is the management of eclampsia?

Management of Eclampsia

Immediate Seizure Control and Stabilization

Administer magnesium sulfate immediately as the first-line anticonvulsant for any woman experiencing eclamptic seizures, with a loading dose of 4-5g IV over 5 minutes, followed by a maintenance infusion of 1-2g/hour for 24 hours after the last seizure or delivery (whichever is later). 1

Magnesium Sulfate Administration Protocol

Loading Dose Options:

• Primary IV regimen: 4-5g IV over 5 minutes in 250mL of 5% dextrose or 0.9% sodium chloride 1, 2
• Combined IV/IM regimen: 4g IV combined with 10g IM (5g in each buttock) for total loading dose of 14g 1
• Alternative IM-only regimen (if IV access unavailable): 10g IM total (5g in each buttock), then refer immediately 1

Maintenance Dose:

• Standard: 1-2g/hour continuous IV infusion for 24 hours after last seizure or delivery 1, 2
• Alternative IM regimen (Pritchard): 5g IM every 4 hours in alternating buttocks when IV infusion pumps unavailable 1, 2
• Recent evidence suggests women receiving ≥8g MgSO4 before delivery may not require full 24-hour postpartum continuation, though 24-hour continuation remains standard until further validation 1

Critical Administration Guidelines:

• Rate of IV injection should not exceed 150mg/minute except in severe eclampsia with active seizures 2
• Solutions for IV infusion must be diluted to 20% concentration or less 2
• Do not continue magnesium sulfate beyond 5-7 days as this causes fetal skeletal demineralization, osteopenia, and neonatal fractures 2

Blood Pressure Management

Initiate IV antihypertensive therapy immediately when BP ≥160/110 mmHg persists for more than 15 minutes, targeting BP <160/105 mmHg (ideally systolic 110-140 mmHg and diastolic 85 mmHg). 1

First-Line Antihypertensive Agents

Labetalol (preferred):

• Initial: 20mg IV bolus 1
• Then: 40mg after 10 minutes 1
• Then: 80mg every 10 minutes to maximum 220mg 1

Nicardipine:

• Start: 5mg/hour 1
• Increase: 2.5mg/hour every 5-15 minutes to maximum 15mg/hour 1

Hydralazine (alternative when labetalol/nicardipine unavailable):

• Can be used as third-line IV agent 1

Oral alternatives (when IV unavailable):

• Methyldopa or nifedipine are acceptable 1
• Avoid short-acting oral nifedipine, especially with concurrent magnesium sulfate, due to risk of uncontrolled hypotension 3

Medications to Absolutely Avoid

• Sodium nitroprusside: Risk of fetal cyanide toxicity (use only as last resort in extreme emergencies) 1, 3
• Diuretics: Plasma volume already reduced in preeclampsia 1
• ACE inhibitors, ARBs, direct renin inhibitors: Severe fetotoxicity 3

Critical Monitoring Requirements

Maternal Monitoring to Prevent Magnesium Toxicity

Before each magnesium dose, assess:

• Patellar (knee jerk) reflexes: Loss of reflexes occurs at 3.5-5 mmol/L and is first warning sign of toxicity—discontinue magnesium if absent 1, 2, 4
• Respiratory rate: Must be ≥16 breaths/minute; respiratory paralysis occurs at 5-6.5 mmol/L 1, 2, 4
• Urine output: Must be ≥100mL over preceding 4 hours (or >35mL/hour via Foley catheter) 1, 2
• Oxygen saturation: Maintain >95% on room air 3

Therapeutic magnesium levels: 1.8-3.0 mmol/L (or 3-6 mg/100mL) for seizure control 1, 4

Magnesium toxicity progression:

• 3.5-5 mmol/L: Loss of deep tendon reflexes 4
• 5-6.5 mmol/L: Respiratory paralysis 4

• 7.5 mmol/L: Altered cardiac conduction 4

• 12.5 mmol/L: Cardiac arrest 4

Antidote: Keep injectable calcium salt (calcium gluconate or calcium chloride) immediately available at bedside to counteract magnesium toxicity 1, 2

Additional Maternal Monitoring

• Blood pressure: Continuous or every 15 minutes until stable, then hourly 1
• Neurological status: Assess for agitation, confusion, unresponsiveness, non-remitting headache 3
• Fluid restriction: 60-80mL/hour total intake to prevent pulmonary edema (replace insensible losses 30mL/hour plus anticipated urine output 0.5-1mL/kg/hour) 1

Laboratory Monitoring

Initial assessment:

• Complete blood count (hemoglobin, platelets) 1
• Liver enzymes (AST, ALT) 1
• Creatinine 1
• Uric acid 1

Repeat frequency:

• At least twice weekly during expectant management 1, 3
• Day after delivery, then every 2 days until stable if abnormal before delivery 1
• More frequently with clinical deterioration 3

Fetal Monitoring

• Continuous fetal heart rate monitoring 1
• Ultrasound at diagnosis: Fetal biometry, amniotic fluid, umbilical artery Doppler 1, 3
• Repeat ultrasound: Every 2 weeks if normal, more frequently if fetal growth restriction present 3

Delivery Planning

Deliver after maternal stabilization with magnesium sulfate and blood pressure control—this is the definitive treatment for eclampsia. 1, 5

Absolute Indications for Immediate Delivery

• Inability to control BP despite ≥3 antihypertensive classes in appropriate doses 1, 3
• Progressive deterioration in liver function, creatinine, hemolysis, or platelet count 1, 3
• Ongoing neurological features (severe intractable headache, repeated visual scotomata, recurrent convulsions) 1, 3
• Pulmonary edema 1, 3
• Placental abruption 1, 3
• Non-reassuring fetal status 1, 3
• Gestational age ≥37 weeks 1, 3
• Maternal pulse oximetry deterioration 3

Delivery Timing by Gestational Age

• ≥37 weeks: Deliver immediately after maternal stabilization 1, 3
• 34-37 weeks: Expectant conservative management appropriate if maternal and fetal status stable; deliver if any deterioration 3
• <34 weeks: Conservative expectant management at center with Maternal-Fetal Medicine expertise only if stable 3
• <24 weeks: Expectant management associated with high maternal morbidity with limited perinatal benefit—counsel regarding pregnancy termination 3

Mode of Delivery

• Vaginal delivery preferred unless cesarean indicated for obstetric reasons 1
• Induction of labor associated with improved maternal outcomes 3
• Neuraxial anesthesia is anesthesia of choice for conscious, seizure-free women with stable vital signs undergoing cesarean section 5

Corticosteroids for Fetal Lung Maturation

• Administer antenatal corticosteroids if gestational age ≤34 weeks 1
• May be given up to 38 weeks for elective cesarean section 1
• Multiple steroid courses not recommended 1

Postpartum Management

Continue magnesium sulfate for 24 hours after delivery or last seizure (whichever is later), as 25-30% of eclampsia cases occur postpartum. 1

Postpartum Monitoring

• Blood pressure: Every 4-6 hours for at least 3 days postpartum 1
• Continue or restart antihypertensives after delivery 1
• Taper antihypertensives slowly only after days 3-6 postpartum unless BP <110/70 mmHg 1

Postpartum Analgesia

• Avoid NSAIDs in women with eclampsia/preeclampsia, especially with acute kidney injury 1
• Use alternative analgesia 1

Long-Term Follow-Up

• Check blood pressure and urine at 6 weeks postpartum 1
• Assess for secondary causes of hypertension in women under 40 with persistent hypertension 1

Special Considerations and Common Pitfalls

Drug Interactions

• Avoid combining magnesium sulfate with calcium channel blockers: Risk of severe hypotension 1
• Caution with neuromuscular blocking agents: Excessive neuromuscular block can occur 2
• Adjust CNS depressants: Reduce dosage of barbiturates, narcotics, hypnotics, or anesthetics due to additive CNS depression 2
• Caution in digitalized patients: Serious cardiac conduction changes and heart block may occur if calcium required to treat magnesium toxicity 2

Renal Impairment

• Maximum dosage 20g/48 hours in severe renal insufficiency 2
• Obtain frequent serum magnesium concentrations 2
• Magnesium removed solely by kidneys—use with extreme caution 2

Resource-Limited Settings

• Pritchard regimen (IM administration) can be used when IV infusion pumps unavailable 1
• Task-shifting allows lower-level providers to initiate loading dose and refer 1
• If IV access unavailable, give IM loading dose and transfer immediately 1

Critical Pitfalls to Avoid

• Do not attempt to diagnose "mild versus severe" preeclampsia clinically—all cases may become emergencies rapidly 3
• Do not use serum uric acid or level of proteinuria as indication for delivery 3
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 3
• Do not use plasma volume expansion routinely for pulmonary edema 3
• Never continue magnesium sulfate beyond 5-7 days due to fetal skeletal toxicity 2