Preeclampsia — Assessment & Classification
A pregnant client's blood pressure reads 148/96 at 34 weeks — but she feels fine. The absence of symptoms doesn't mean the absence of danger. Knowing what to look for next could save two lives.
Core Concept
Preeclampsia is a hypertensive disorder diagnosed after 20 weeks' gestation. The diagnostic threshold is a sustained systolic BP ≥140 mmHg or diastolic ≥90 mmHg on two readings at least 4 hours apart, plus proteinuria (≥300 mg in 24-hour urine or protein/creatinine ratio ≥0.3 mg/mg). Preeclampsia can exist without proteinuria if other end-organ damage is present: thrombocytopenia (platelets <100,000), elevated liver enzymes (AST/ALT twice normal), renal insufficiency (creatinine >1.1 mg/dL), pulmonary edema, or new-onset cerebral or visual disturbances. Severe features include BP ≥160/110, persistent headache unresponsive to medication, right upper quadrant or epigastric pain (hepatic capsule stretch), visual changes (scotomata, blurred vision), and thrombocytopenia. HELLP syndrome — Hemolysis, Elevated Liver enzymes, Low Platelets — is a severe variant often missed because BP may not be dramatically elevated. Assess deep tendon reflexes: hyperreflexia (3+ to 4+) and clonus signal CNS irritability and impending seizure (eclampsia). Edema alone is not diagnostic — many healthy pregnancies include edema — but sudden facial or periorbital swelling with rapid weight gain (>2 lb/week) warrants immediate investigation.
Watch Out For
Don't confuse gestational hypertension (elevated BP without proteinuria or end-organ damage) with preeclampsia — proteinuria or organ involvement is the dividing line. Students often think edema equals preeclampsia; it doesn't. Dependent edema is normal in pregnancy. The red flag is sudden generalized or facial edema plus hypertension. RUQ pain in preeclampsia signals liver involvement (HELLP), not gallbladder disease — context of gestational age and BP matters.
Clinical Pearl
HEAD to toe: Headache, Epigastric pain, Altered vision, DTR hyperreflexia — when a pregnant client after 20 weeks reports any of these, think preeclampsia with severe features until proven otherwise.
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