Purpose: It is controversial whether arterial hypertension (AHT) can be diagnosed in the emergency department (ED). We sought to prospectively investigate the natural time course of blood pressure (BP) to define an optimal period for AHT screening in ED patients with an elevated initial BP.
Procedures: Patients with a BP greater than 160/100 mm Hg upon ED admission underwent repeated BP measurements every 5 minutes for 2 hours using an automated device. Arterial hypertension was confirmed using 12-hour ambulatory BP measurement or repeated office BP measurement according to the Joint National Committee VII guidelines by the primary care physician after discharge from the hospital.
Main findings: Systolic BP decreased significantly during the first 10 to 20 minutes of ED stay in hypertensive and normotensive patients without further significant changes thereafter. Diastolic BP remained stable in both hypertensive and normotensive patients. Discrimination between hypertensive and normotensive patients was best between minutes 60 and 80 after ED admission. An average BP of 165/105 mm Hg or higher during this period strongly suggests AHT whereas a BP of less than 130/80 mm Hg excludes AHT with high sensitivity.
Conclusions: Screening for AHT in the ED is possible with high specificity and sensitivity. Blood pressure measurements between minutes 60 and 80 after entry into the ED yield the highest diagnostic value.