Eclampsia Management
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Direct answer
Eclampsia is a generalised tonic-clonic convulsion in a woman with preeclampsia, most often in the third trimester or intrapartum but also up to several weeks after delivery. Immediate care follows ABC — left lateral position, airway and oxygen support — plus magnesium sulphate, the anticonvulsant of choice that the Collaborative Eclampsia Trial proved superior to diazepam and phenytoin. The Indian Pritchard regimen loads with 4 g intravenous magnesium sulphate slowly plus 10 g intramuscularly (5 g each buttock), then maintains with 5 g intramuscularly every 4 hours, monitored by reflexes, a respiratory rate of 16 or more and urine output of 25 to 30 mL per hour, with 10% calcium gluconate as antidote. Once stabilised, delivery is planned — convulsions are no bar to vaginal birth when conditions favour it.
What you must remember
- Definition: seizures in a preeclamptic woman not attributable to other causes, typically after 20 weeks, some up to about four weeks postpartum (late eclampsia); fits occur before, during and after delivery.
- Impending signs: severe headache, visual blurring, epigastric pain, vomiting and hyperreflexia.
- Pritchard regimen: 4 g slow IV plus 10 g IM loading (5 g per buttock), then 5 g IM 4-hourly; Zuspan regimen: 4 g IV loading then 1 to 2 g per hour infusion.
- Toxicity ladder: reflexes vanish around 9 to 10 mEq/L, respiratory depression around 12, cardiac arrest higher; monitoring is clinical — reflexes present, respirations at least 16, urine at least 25 to 30 mL per hour.
- Antidote: calcium gluconate 10%, 10 mL intravenously, with airway and breathing support at the first sign of toxicity.
- Control blood pressure of 160/110 or more with intravenous labetalol or hydralazine, restrict fluids, and deliver once stable.
- Killers: cerebral haemorrhage, pulmonary oedema and aspiration; perinatal loss follows prematurity, abruption and placental insufficiency.
Common confusion
The classic error is reaching for diazepam or phenytoin — magnesium sulphate treats and prevents fits and beat both in the Collaborative Eclampsia Trial. The second trap is stopping magnesium too early: current guidance continues 24 hours after delivery or the last fit. A postpartum fit with hypertension is still eclampsia, not epilepsy, until proved otherwise.
Exam-focused takeaway
FMGE eclampsia questions are regimen and safety numbers: Pritchard loading (4 g IV + 10 g IM), 4-hourly 5 g maintenance, the monitoring triad, and calcium gluconate as antidote. Expect the emergency vignette — a convulsing primigravida — answered by left lateral position, airway care, magnesium loading, blood pressure control and delivery after stabilisation. The timing question (fits after delivery) and the magnesium-versus-diazepam comparison repeat almost every cycle.
Frequently asked questions
What is the drug of choice for eclampsia?
Magnesium sulphate, which controls and prevents fits better than diazepam or phenytoin, as shown by the Collaborative Eclampsia Trial.
What is the Pritchard regimen?
Loading with 4 g magnesium sulphate slow IV plus 10 g IM (5 g into each buttock), then 5 g IM every 4 hours, continuing 24 hours after delivery or the last fit.
How is magnesium toxicity detected and treated?
Clinically — loss of patellar reflexes around 9 to 10 mEq/L, then respiratory depression below 16 per minute and falling urine output; treat with calcium gluconate 10% 10 mL IV, stopping magnesium and supporting respiration.
Can eclampsia occur after delivery?
Yes — fits are common within 48 hours of birth, and late eclampsia appears up to about four weeks postpartum, so hypertensive postpartum women remain under watch.
When is the eclamptic mother delivered?
Once stabilised — seizures controlled, airway safe, severe hypertension treated — with the route decided obstetrically; vaginal delivery is acceptable in advanced labour with a stable fetus.