Severe Preeclampsia

Severe preeclampsia is preeclampsia with sustained blood pressure of 160/110 mmHg or more, or with symptoms or laboratory evidence of end organ injury. It is a life-threatening emergency that can become eclampsia, stroke or HELLP syndrome within hours. It is an important cause of maternal death in sub-Saharan Africa.

• Risk factors: previous preeclampsia, chronic hypertension, kidney disease, diabetes, twin pregnancy, lupus, antiphospholipid syndrome.
• Magnesium sulphate and rapid blood pressure control save lives.
• Delivery after stabilisation is the definitive treatment.

Women have severe headache, visual disturbance, upper abdominal pain, vomiting, breathlessness and reduced urine, with hyperreflexia and clonus. Blood pressure is 160/110 mmHg or more on two readings 15 minutes apart.

• Urine protein 2 plus or more is common.
• Pulmonary crackles suggest oedema.
• Differential diagnosis: eclampsia, HELLP syndrome, acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, hypertensive encephalopathy, intracranial haemorrhage, phaeochromocytoma.
• Complications: eclampsia, stroke, pulmonary oedema, HELLP syndrome, acute kidney injury, abruption, liver rupture, disseminated intravascular coagulation, stillbirth, maternal death.

The diagnosis is clinical and is confirmed by tests that should not delay treatment.

• Blood pressure 160/110 mmHg or more with proteinuria or organ dysfunction after 20 weeks.
• Full blood count and film, creatinine, urea, liver enzymes, lactate dehydrogenase, bilirubin, uric acid, coagulation screen, fibrinogen, group and cross-match.
• Oxygen saturation, urine output; ultrasound with Doppler; cardiotocography.
• Repeat blood tests every 6 to 12 hours.

The principle is magnesium sulphate, blood pressure control within 30 to 60 minutes, stabilisation and delivery.

• Supportive: admit to a high dependency area; call senior staff; left lateral position; oxygen if saturation is below 94 percent; two cannulae; urinary catheter with hourly output; restrict total fluids to 80 mL per hour; check reflexes, respiratory rate and urine output hourly during magnesium infusion.
• Pharmacological: magnesium sulphate 4 g IV over 20 minutes then 1 g per hour for 24 hours after birth, or where infusion is not possible give 4 g IV plus 10 g IM (5 g in each buttock) then 5 g IM 4-hourly; recurrent seizure 2 g IV over 5 minutes; stop magnesium for absent patellar reflexes, respiratory rate below 12 per minute or urine below 30 mL per hour and give calcium gluconate 1 g IV over 10 minutes for toxicity; labetalol 20 mg IV over 2 minutes then 40 mg, 80 mg and 80 mg at 10 minute intervals (maximum 220 mg) or nifedipine immediate release 10 mg oral repeated after 30 minutes or hydralazine 5 mg IV then 5 to 10 mg every 20 to 30 minutes (maximum 20 mg), aiming for 140 to 150/90 to 100 mmHg; betamethasone 12 mg IM twice, 24 hours apart, below 34 weeks; furosemide 40 mg IV for pulmonary oedema; oxytocin 10 IU IM after birth and no ergometrine.
• Procedures: delivery within 24 hours of stabilisation, immediately for abruption, pulmonary oedema, eclampsia or fetal compromise; induction with misoprostol 25 micrograms vaginal 6-hourly (maximum 4 doses) or Foley catheter, or caesarean section when vaginal birth will not occur within 24 hours; platelet transfusion for below 50 x 10^9/L before caesarean section.
• Special groups: kidney disease reduces magnesium to 0.5 g per hour with level monitoring; asthma uses nifedipine instead of labetalol; platelets below 70 x 10^9/L contraindicate spinal anaesthesia.
• Red flags: seizure, blood pressure not responding to 2 drugs, saturation below 94 percent, oliguria, bleeding, falling platelets, fetal bradycardia.
• Follow-up: high dependency care for 24 to 48 hours after birth; blood pressure at 6 hours, daily for 5 days, then at 2 and 6 weeks; blood tests daily until normal; review at 6 weeks and counsel on recurrence.