Pre-eclampsia & Eclampsia for the Nurse Practitioner Licensing Exam
Overview of Pre-eclampsia and Eclampsia
- Definitions:
- Pre-eclampsia: New-onset hypertension (≥140/90 mmHg) occurring after 20 weeks’ gestation with proteinuria (≥300 mg/24-hour urine or protein/creatinine ratio ≥0.3) or signs of systemic organ dysfunction (e.g., thrombocytopenia, liver enzyme elevation).
- Eclampsia: Occurrence of generalized tonic-clonic seizures in a patient with pre-eclampsia not explained by other neurological conditions.
- Classification:
- Mild Pre-eclampsia: Blood pressure <160/110 mmHg without severe symptoms.
- Severe Pre-eclampsia: Blood pressure ≥160/110 mmHg or symptoms like severe headache, visual disturbances, right upper quadrant pain, or pulmonary edema.
Pathophysiology
- Abnormal Placental Development:
- Poor placental implantation leads to reduced perfusion, ischemia, and release of antiangiogenic factors that cause endothelial dysfunction.
- Endothelial injury promotes vasoconstriction, increased vascular permeability, and pro-coagulant activity, resulting in hypertension and proteinuria.
Clinical Presentation
- Symptoms:
- Mild Pre-eclampsia: May be asymptomatic or show mild edema and headache.
- Severe Pre-eclampsia: Severe headache, blurred vision, right upper quadrant pain, dyspnea, and edema.
- Signs of Eclampsia:
- Tonic-clonic seizures in a patient with pre-eclampsia; often preceded by hyperreflexia or visual changes.
Diagnostic Evaluation
- Laboratory Testing:
- Urinary Protein: ≥300 mg/24-hour urine or protein-to-creatinine ratio ≥0.3.
- CBC: Thrombocytopenia (<100,000/mcL) indicates severe disease.
- Liver Enzymes and Renal Function: Elevated AST/ALT and creatinine suggest organ involvement.
Management and Treatment
- Blood Pressure Control:
- Target BP: <160/110 mmHg to avoid complications.
- Medications: Labetalol, nifedipine, or hydralazine are first-line.
- Seizure Prophylaxis and Treatment:
- Magnesium Sulfate: Administered for seizure prevention and control, with careful monitoring for toxicity (respiratory rate, reflexes).
- Delivery Timing:
- For severe cases, delivery is recommended at ≥34 weeks or earlier if maternal/fetal status worsens.
Key Points
- Pre-eclampsia is characterized by new-onset hypertension and proteinuria or organ dysfunction after 20 weeks; eclampsia involves seizures.
- Severe pre-eclampsia presents with BP ≥160/110 mmHg, severe headache, or visual changes.
- Management includes BP control, magnesium sulfate for seizure prophylaxis, and delivery if needed.
- Major complications include HELLP syndrome, pulmonary edema, and risk of intrauterine growth restriction (IUGR) for the fetus.