Preeclampsia with Severe Features

Preeclampsia with severe features is preeclampsia with blood pressure of 160/110 mmHg or more, or with organ involvement (platelets below 100 x 10^9/L, liver enzymes twice normal, creatinine above 90 micromol/L, pulmonary oedema, or new severe headache or visual disturbance). It is an obstetric emergency because eclampsia, stroke and abruption can develop within hours.

• Risk factors: previous preeclampsia, chronic hypertension, kidney disease, diabetes, twin pregnancy, antiphospholipid syndrome.
• Magnesium sulphate greatly lowers the risk of eclampsia.
• Delivery follows stabilisation.

Women may have severe headache, blurred vision, scotomata, epigastric or right upper quadrant pain, vomiting, breathlessness, reduced urine and hyperreflexia with clonus. Others have no symptoms but severe hypertension.

• Blood pressure 160/110 mmHg or more on two readings 15 minutes apart.
• Pulmonary oedema with crackles and low saturation.
• Differential diagnosis: eclampsia, HELLP syndrome, acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, hypertensive encephalopathy, phaeochromocytoma, lupus nephritis.
• Complications: eclampsia, stroke, HELLP syndrome, abruption, pulmonary oedema, acute kidney injury, liver rupture, disseminated intravascular coagulation, stillbirth, maternal death.

The diagnosis is made on any one severe criterion with preeclampsia.

• Blood pressure 160/110 mmHg or more; platelets below 100 x 10^9/L; alanine or aspartate aminotransferase twice the upper limit; creatinine above 90 micromol/L or doubled; pulmonary oedema; new headache not responding to paracetamol; visual disturbance.
• Full blood count, film for fragments, creatinine, liver enzymes, lactate dehydrogenase, bilirubin, uric acid, coagulation screen and fibrinogen, group and cross-match, urine protein to creatinine ratio.
• Ultrasound with umbilical artery Doppler; cardiotocography.
• Repeat blood tests every 6 to 12 hours.

The principle is magnesium sulphate, rapid blood pressure control, stabilisation and delivery.

• Supportive: admit to a high dependency area; 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.
• 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; for a repeat seizure give 2 g IV over 5 minutes; stop magnesium if patellar reflexes are absent, respiratory rate is below 12 per minute or urine is below 30 mL per hour, and give calcium gluconate 1 g IV (10 mL of 10 percent) 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 if needed, or hydralazine 5 mg IV then 5 to 10 mg every 20 to 30 minutes (maximum 20 mg), to bring blood pressure to 140 to 150/90 to 100 mmHg; betamethasone 12 mg IM twice, 24 hours apart, before 34 weeks; oxytocin 10 IU IM after birth and no ergometrine.
• Procedures: delivery within 24 hours of stabilisation, at once for eclampsia, abruption, pulmonary oedema or fetal compromise; induction with misoprostol 25 micrograms vaginal 6-hourly (maximum 4 doses) or Foley catheter, or caesarean section if vaginal birth is not expected within 24 hours; transfuse platelets for below 50 x 10^9/L before caesarean section.
• Special groups: kidney disease reduces magnesium to 0.5 g per hour with serum levels; asthma uses nifedipine instead of labetalol; platelets below 70 x 10^9/L contraindicate spinal anaesthesia, and general anaesthesia needs blunting of the pressor response.
• Red flags: seizure, blood pressure 160/110 mmHg or more despite treatment, oxygen saturation below 94 percent, oliguria, platelets falling, bleeding, fetal bradycardia.
• Follow-up: high dependency care for 24 hours after birth; blood pressure at 6 hours, daily for 5 days, then at 2 and 6 weeks; blood tests daily until normalising; review at 6 weeks and annually.