A 28-year-old pregnant woman at 32 weeks gestation presents to the labor and delivery unit with complaints of severe headache, blurred vision, and epigastric pain. Her blood pressure is 160/110 mmHg, and she has 3+ proteinuria. Which assessment finding would be most concerning and require immediate intervention?

Hyperreflexia with sustained clonus indicates severe CNS irritability and imminent risk of eclamptic seizures, requiring immediate magnesium sulfate administration. Other findings (hypertension, proteinuria, edema) are typical of severe preeclampsia but less urgent.

Clinical Reasoning & Priority Setting

The assessment finding that is most concerning and requires immediate intervention is hyperreflexia with sustained clonus. This finding is a hallmark of severe central nervous system (CNS) irritability, which signals a rapid progression from severe preeclampsia to eclampsia, a life-threatening obstetric emergency characterized by generalized tonic-clonic seizures .

The pathophysiology underlying this progression involves disrupted cerebral autoregulation. In severe preeclampsia, systemic vasospasm and endothelial dysfunction lead to increased cerebral perfusion pressure. When the mean arterial pressure exceeds the brain's ability to constrict vessels, forced vasodilation and hyperperfusion occur, resulting in cerebral edema. This neuronal irritability manifests clinically as hyperreflexia and, in its most extreme form, sustained ankle clonus, indicating that the seizure threshold is critically low . While a blood pressure of 160/110 mmHg (Option 2) defines the severe range and requires antihypertensive therapy, the presence of clonus signifies impending eclampsia and demands emergent seizure prophylaxis, typically with intravenous magnesium sulfate, taking priority over blood pressure control alone . Similarly, 3+ proteinuria (Option 3) confirms the diagnosis of preeclampsia but does not, by itself, dictate the immediate risk of an eclamptic seizure. Ankle edema with a weight gain of 2 pounds in one week (Option 1) is a common finding related to generalized vasospasm and capillary leak, but it is not a direct indicator of imminent neurological deterioration. Therefore, the nurse must recognize that CNS signs take precedence in the clinical staging of severe preeclampsia, as the prevention of maternal seizures is the critical safety goal .