What is the management for high blood pressure (hypertension) in preeclampsia?

Management of High Blood Pressure in Preeclampsia

Blood pressure in preeclampsia requires urgent treatment in a monitored setting when severe (>160/110 mm Hg) using oral nifedipine or intravenous labetalol or hydralazine as first-line agents. 1

Diagnosis and Initial Assessment

• Preeclampsia is diagnosed by hypertension (BP ≥140/90 mmHg) after 20 weeks gestation with proteinuria (≥30 mg/mmol or 0.3 mg/mg protein/creatinine ratio) 1
• Initial assessment should include:
  • Blood pressure monitoring
  • Proteinuria assessment
  • Clinical assessment including clonus
  • Laboratory tests: hemoglobin, platelet count, liver enzymes, renal function, and uric acid 1
  • Fetal assessment to confirm well-being 1

Management Algorithm for Hypertension in Preeclampsia

1. Severe Hypertension (>160/110 mmHg) - URGENT Treatment Required:

• First-line medications (in monitored setting): 1, 2
  • IV labetalol: 20 mg IV bolus, then 40 mg 10 minutes later, 80 mg every 10 minutes for 2 additional doses to maximum 220 mg
  • IV hydralazine: 5 mg IV bolus, then 10 mg every 20-30 minutes to maximum 25 mg
  • Oral nifedipine: 10 mg PO, repeat every 20 minutes to maximum 30 mg
• Second-line agent (rarely, when others fail):
  • Sodium nitroprusside: 0.25μg/kg/min to maximum 5μg/kg/min (caution: fetal cyanide poisoning risk if used >4 hours) 1

2. Non-Severe Hypertension (140-159/90-109 mmHg):

• Target diastolic BP of 85 mmHg (systolic 110-140 mmHg) 1
• First-line oral agents: 1, 2
  • Methyldopa
  • Labetalol
  • Oxprenolol
  • Nifedipine
• Second/third-line agents: hydralazine and prazosin 1
• Reduce or cease antihypertensives if diastolic BP falls <80 mmHg 1

Additional Management Measures

Seizure Prophylaxis:

• Magnesium sulfate for women with preeclampsia who have: 1, 2
  • Proteinuria and severe hypertension
  • Hypertension with neurological signs/symptoms
  • Loading dose: 4-5g IV over 15-20 minutes
  • Maintenance: 1-2g/hour continuous infusion 2

Maternal Monitoring:

• BP monitoring
• Repeated proteinuria assessment
• Clinical assessment including clonus
• Blood tests at least twice weekly: hemoglobin, platelets, liver and renal function, uric acid 1
• Monitor in high-dependency or intensive care setting for 24-48 hours for severe cases 2

Fetal Monitoring:

• Initial assessment to confirm fetal well-being
• In fetal growth restriction: serial fetal surveillance with ultrasound 1
• Serial evaluation of fetal growth every 2 weeks 2
• Corticosteroids for fetal lung maturation if <34 weeks pregnant 2

Delivery Considerations

Delivery is indicated for women with preeclampsia if: 1, 2

• Reached 37 weeks' gestation
• Repeated episodes of severe hypertension despite treatment with 3 classes of antihypertensives
• Progressive thrombocytopenia
• Progressively abnormal renal or liver enzyme tests
• Pulmonary edema
• Abnormal neurological features
• Non-reassuring fetal status

Postpartum Management

• Continue BP monitoring every 4-6 hours for at least 3 days 2
• Taper antihypertensive medications slowly after days 3-6 2
• Follow-up within 1 week if still on antihypertensives at discharge 2
• Review at 3 months postpartum 2
• Annual medical review recommended lifelong 2

Important Caveats

• Do not attempt to distinguish between "mild" and "severe" preeclampsia clinically, as all cases can rapidly progress to emergencies 2
• Do not discontinue close monitoring even if condition appears stable 2
• Volume expansion is not recommended routinely 2
• Do not delay delivery beyond 37 weeks in women with preeclampsia without severe features 2
• Preeclampsia rarely remits spontaneously and in most cases worsens with time 1

Remember that preeclampsia is more than just hypertension—it's a multisystem disorder that requires comprehensive management to prevent maternal and fetal complications.