What is the emergency management for a pregnant woman at ≥20 weeks gestation presenting with preeclampsia?

Emergency Management of Preeclampsia

Women presenting with preeclampsia at ≥20 weeks gestation require immediate assessment for severe features, urgent blood pressure control if BP ≥160/110 mmHg, magnesium sulfate for seizure prophylaxis when severe features are present, and delivery planning based on gestational age and disease severity. 1

Immediate Stabilization and Assessment

Blood Pressure Management

• Initiate urgent antihypertensive therapy immediately when BP ≥160/110 mmHg persists for >15 minutes to prevent maternal cerebral hemorrhage. 1, 2
• First-line IV options include:
  • IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg) 1
  • IV hydralazine: 5-10 mg IV every 20 minutes as needed 1
  • Oral nifedipine is preferred for urgent BP control when IV access is not immediately available 2
• Target BP: systolic 110-140 mmHg and diastolic 85 mmHg (or at minimum <160/105 mmHg). 1, 2, 3
• For non-severe hypertension (BP 140-159/90-109 mmHg), use oral agents: methyldopa, labetalol, or nifedipine 1

Seizure Prophylaxis with Magnesium Sulfate

• Administer magnesium sulfate immediately to all patients with severe preeclampsia, proteinuria plus severe hypertension, or any neurological symptoms (headache, visual changes). 1, 2, 3
• Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 1
• Maintenance: 1-2 g/hour continuous IV infusion 1
• Continue for 24 hours postpartum, as eclampsia can occur in the postpartum period 2

Identify Severe Features Requiring Urgent Intervention

Severe features include any of the following: 1, 2

• Severe hypertension: BP ≥160/110 mmHg on two occasions at least 15 minutes apart
• Thrombocytopenia: platelets <100,000/μL
• Renal dysfunction: creatinine >1.1 mg/dL or doubling of baseline
• Liver involvement: elevated transaminases (AST/ALT ≥2x upper limit of normal) 1
• Neurological symptoms: severe headache, visual disturbances (scotomata, cortical blindness), altered mental status
• Pulmonary edema 1, 2
• Epigastric or right upper quadrant pain (hallmark of HELLP syndrome) 1, 2

Comprehensive Laboratory Assessment

Obtain immediately: 1, 2, 3

• Complete blood count with focus on hemoglobin and platelet count
• Comprehensive metabolic panel: liver transaminases (AST/ALT), creatinine, uric acid
• Spot urine protein/creatinine ratio (≥30 mg/mmol confirms proteinuria, though proteinuria is no longer mandatory for diagnosis) 1

Fetal Assessment

• Continuous electronic fetal heart rate monitoring to assess for non-reassuring fetal status 2, 3
• Biophysical profile including ultrasound assessment of fetal biometry, amniotic fluid volume, fetal breathing movements, body movements, and tone 3
• Non-reassuring fetal status is an absolute indication for immediate delivery regardless of gestational age 1, 2

Delivery Timing: Gestational Age-Based Algorithm

At ≥37 Weeks Gestation

• Deliver immediately after maternal stabilization regardless of severity or laboratory values. 1, 3
• Do not delay delivery based on non-reactive NST—delivery is indicated regardless of fetal testing results 3

At 34-37 Weeks Gestation

• Without severe features: expectant management with close monitoring is appropriate 1
• With severe features: deliver after maternal stabilization 1, 3

At <34 Weeks Gestation

• Expectant management is possible in select cases under intensive monitoring 4, 5
• Administer corticosteroids for fetal lung maturity between 24-34 weeks 4

Absolute Indications for Immediate Delivery (Any Gestational Age)

Deliver immediately regardless of gestational age if: 1, 2

• Inability to control BP despite ≥3 classes of antihypertensives in appropriate doses
• Eclamptic seizures (after maternal stabilization with magnesium sulfate)
• Progressive thrombocytopenia (declining platelet counts on serial measurements) 1
• Progressively abnormal liver or renal function tests (worsening trends, not static elevations) 1
• Placental abruption
• Non-reassuring fetal status on continuous monitoring
• Pulmonary edema
• Maternal oxygen saturation deterioration (<90%)

Special Considerations for HELLP Syndrome

• HELLP syndrome is defined by hemolysis, elevated liver enzymes (AST/ALT ≥2x upper limit), and low platelets (<100,000/μL) 1
• Maternal mortality rate is 3.4% in HELLP syndrome 1, 2
• Epigastric or right upper quadrant pain is the hallmark symptom 1, 2
• Monitor glucose intraoperatively as severe hypoglycemia can occur 1
• HELLP syndrome should be managed as severe preeclampsia with immediate delivery planning 1

Management of Pulmonary Edema

• Drug of choice is IV nitroglycerin (glycerol trinitrate) starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min 1, 6
• Limit fluid balance to 60-80 mL/hour to avoid worsening pulmonary edema, with target urine output of 0.5-1 mL/kg/hour 2
• Plasma volume expansion is NOT recommended routinely 1

Monitoring Protocol

Maternal Monitoring

• Blood pressure: at least every 4 hours while awake, or continuously if severe features present 1, 2
• Laboratory tests: repeat at least twice weekly (hemoglobin, platelets, liver enzymes, creatinine, uric acid) 1
• Assess for visual disturbances, epigastric/right upper quadrant pain, headache 2
• Monitor fluid balance and urine output 2, 6

Setting of Care

• Women with severe features should be managed in facilities with appropriate obstetrical care, maternal intensive care capabilities, and NICU for premature infants. 1

Critical Pitfalls to Avoid

• Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress to life-threatening complications 1, 2, 3
• Blood pressure alone is not a reliable indicator of disease severity—serious organ dysfunction can develop at relatively mild levels of hypertension 1, 3
• Do not use serum uric acid or level of proteinuria as indication for delivery 1
• Do not delay delivery at ≥37 weeks based on non-reactive NST—delivery is indicated regardless of fetal testing results 3
• Do not reduce antihypertensives if diastolic BP falls <80 mmHg 1
• Do not use diuretics routinely—they further reduce plasma volume which is already contracted in preeclampsia 1
• Avoid NSAIDs for postpartum analgesia unless other analgesics are not working, especially if renal disease or placental abruption are present 2

Postpartum Management

• Continue magnesium sulfate for 24 hours postpartum 2
• Monitor BP at least every 4-6 hours for at least 3 days postpartum 2
• Continue neurological monitoring as postpartum eclampsia remains a risk 2
• Repeat laboratory tests the day after delivery and then every other day until stable 2
• Review all women at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 1