Treat BP ≥ 160/110 within 30-60 min, give magnesium sulfate (Pritchard or Zuspan), restrict fluids, manage seizures and plan delivery.
At the bedside
Timed steps- 1
Eclamptic seizure
0 minLeft lateral position, airway, oxygen; magnesium 4 g IV over 15-20 min (do not use diazepam first-line). Recurrent seizure: further 2 g IV.
- 2
Treat severe hypertension
≤ 60 minBP ≥ 160/110 confirmed over 15 min: labetalol IV, hydralazine IV or oral immediate-release nifedipine within 30-60 min; target 135/85 (NICE) and < 160/110.
- 3
Magnesium prophylaxis
All severe pre-eclampsia (during labour/delivery and 24 h after): Pritchard or Zuspan regimen; monitor reflexes, RR, urine output; check levels if oliguric.
- 4
Fluid restriction
Total fluids about 80 mL/h unless ongoing losses (risk of pulmonary oedema); strict input-output.
- 5
Investigations
FBC, LFT, LDH, creatinine, uric acid, coagulation, urine protein:creatinine ratio; CT/MRI brain if focal signs, seizures after 48 h postpartum or atypical (PRES, stroke, CVT).
- 6
Deliver
Delivery is definitive; after stabilisation (≥ 34 weeks or maternal compromise at any gestation); steroids for fetal lung maturity if < 34 weeks and time allows.
- 7
Postpartum
Continue BP monitoring; risk of eclampsia and stroke persists for days; switch to oral agents (nifedipine/amlodipine, labetalol, enalapril postpartum).
Eclampsia / severe pre-eclampsia (Zuspan)
Magnesium sulfate
- Dose
- 4 g over 15-20 min, then 1 g/h for 24 h
- Preparation
- Load: 8 mL of 50% + 12 mL NS (20 mL of 20%); maintenance 25 g (50 mL of 50%) in 500 mL = 50 mg/mL
- Worked example
- 1 g/h = 20 mL/h of 50 mg/mL solution
Pritchard regimen (India)
Magnesium sulfate
- Dose
- 4 g IV + 5 g IM each buttock, then 5 g IM 4-hourly alternate buttocks
- Worked example
- 5 g = 10 mL of 50% per buttock (add 1 mL 2% lidocaine)
Severe hypertension
Labetalol
- Dose
- 20 mg, then 40 mg, then 80 mg every 10 min (max 300 mg)
- Worked example
- 20 mg = 4 mL of 5 mg/mL over 2 min
Severe hypertension
Hydralazine
- Dose
- 5-10 mg over 2 min, repeat after 20 min
Severe hypertension (no IV)
Nifedipine (immediate-release oral)
- Dose
- 10 mg, then 20 mg after 20 min, then 20 mg
Magnesium toxicity
Calcium gluconate 10%
- Dose
- 1 g (10 mL 10%) over 10 min
Calculators for this topic
References
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Severe pre-eclampsia / eclampsia
Step 1 of ~6
Decision: Seizure now?
Based on American College of Obstetricians and Gynecologists. Educational use; follow local protocol.
Pathophysiology
Abnormal placentation with impaired spiral artery remodelling causes placental ischaemia and release of anti-angiogenic factors (sFlt-1, soluble endoglin), producing systemic endothelial dysfunction, vasoconstriction, capillary leak, glomerular endotheliosis and cerebral autoregulatory failure (PRES).
Evidence
- Magpie (10,141 women): magnesium halved eclampsia risk (RR 0.42) [Magpie 2002].
- ACOG 2020 and ISSHP 2021 guidance on BP thresholds, agents and timing of delivery [ACOG 2020; Magee 2022].
- NICE NG133 BP target 135/85 and fluid restriction [NICE 2019].
Controversies
- 12 vs 24 h postpartum magnesium; Pritchard vs Zuspan; sFlt-1/PlGF testing.
🇮🇳 India notes
- Hypertensive disorders are a leading direct cause of maternal death in India. The Pritchard (IM) regimen is widely used because infusion pumps may be unavailable; MoHFW and FOGSI recommend loading dose before referral from peripheral centres.
- Late presentation with eclampsia and PRES is common in rural India.
References
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