ESMOE: Pre-eclampsia and Eclampsia

Recognising severe pre-eclampsia
Magnesium sulphate
Principles of management
Fluid management
Investigations
Anti-hypertensive treatment options

Recognising severe pre-eclampsia

• BP >140/90
• Proteinuria 3+ or more
• Headache
• Blurred vision
• Epigastric/upper abdominal pain
• Hyperreflexia, clonus
• Jittery
• Breathlessness (pulmonary oedema)
• Reduced urine output (less than 25ml/hour or less than 100ml/4 hours)

Principles of management

The cure the pre-eclampsia (& eclampsia) is delivery of the fetus & placenta. However a planned delivery in a stable patient is safer than a rushed delivery in an unstable patient. Maternal complications of pre-eclampsia include CVA, pulmonary oedema, renal failure and HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome. Fetal complications include intrauterine growth restriction, hypoxia & death. The aims of the investigations & management of pre-eclampsia are to minimise the chances of these complications arising, identifying them early & treating them appropriately when they do occur.

Magnesium sulphate

Consider if transferring, severe pre-eclampsia or imminent eclampsia. Give in all cases of eclampsia (fitting/convulsions)

Loading dose is given IV and IM:

• 4g (diluted in 200ml normal saline) 20% solution over 20 minutes
• 10g IM (add 1ml of 2% lignocaine) 50% solution - give 5g to each buttock

Maintenance dose until 24 hours after delivery or last fit

• 5g IM (50% solution) 4 hourly to alternating buttocks

Recurring fits:

• additional 2g magnesium sulphate IV (20% solution)

Monitor patellar tendon reflex, urine output and respiratory rate. Stop magnesium sulphate and consider antidote (10ml of 10% calcium gluconate) if:

• absent knee jerk
• urinary output is less than 100ml/4 hours
• respiratory rate less than 16/minute

Fluid management

• Catheterise
• Monitor fluid input & output
• 300ml IV fluid bolus - 200ml normal saline with magnesium sulphate then 100ml Ringers Lactate (RL) run 1 hour
• Maintenance fluids - RL at 80ml/hour
• If urine output <30ml/hour give 200ml RL bolus
• If urine output continues to be <30ml/hour reduce maintenance fluids to 80ml/hour

Delivery: vaginal delivery is recommended. Assess the cervix & start induction. If the patient is not established in labour within 8 hours perform a CS. Caesarean section is advised if there are repeat fits, maternal risks, fetal distress or an unfavourable cervix. Give steroids to promote lung maturity if less than 37 weeks gestation.

Investigations

• Haematocrit
• Platelets
• Creatinine
• AST
• 24 hour urinary protein
• Fetal heart (once mother is stabilised)

Anti-hypertensive treatment options

• Oral - Nifedipine 10mg stat - repeat @15 min x 3. NOT sublingual (contraindicated if pulse >120 bpm, cardiac lesion, unable to swallow)
• IV - Labetalol 20, 40, 80, 80, 80 mg (contraindicated in asthma, IHD) every 15 minutes
• Aim to reduce BP to <160 - 110 mm Hg