Detection of hypertension in the emergency department

OBJECTIVES: To assess whether an emergency department (ED) is a suitable location for the targeted screening of hypertension. METHODS: This was a prospective targeted screening study based at the ED of an inner city teaching hospital. Non-acute subjects over 18 years were recruited consecutively from the "minors" section of the ED and invited to participate. All subjects had their blood pressure measured twice. A verbal numerical pain score (PS) out of 10 using a visual analogue scale was obtained. Those with a mean systolic blood pressure > 140 mmHg or a mean diastolic blood pressure > 90 mmHg (WHO JNC stage 1 hypertension) were invited for a subsequent follow up measurement. The primary outcome measure was the proportion of subjects with hypertension at follow up. The secondary outcome measure was the correlation between a subject's mid blood pressure (MBP) and their PS. RESULTS: In total, 765 subjects were tested, of whom 213 subjects were hypertensive at presentation (28.7%). After excluding those on anti-hypertensive medication (n = 43; 5.6%) and those who were non-UK residents (n = 44; 5.8%), 126 subjects were invited for follow up, of whom 51 subjects actually attended (40% attendance, 6.6% of study population). The MBP of those who re-attended was significantly lower than at presentation (p < 0.001); 39 subjects (5% of the study population, 76.4% of those attending follow up) remained hypertensive. There was no correlation between a subject's PS and their MBP (Pearson correlation coefficient = -0.02). A 10/10 PS was associated with an 8.4 mmHg rise in MBP compared to the mean MBP of subjects with PS 0-9 (p < 0.1). Of those originally presenting with PS > 5/10, 62% still had hypertension at follow up when the painful stimulus was significantly reduced (mean PS = 0.6). CONCLUSION: The ED provides an opportunity for identifying those individuals with hypertension who may otherwise remain undiagnosed. Caution is advised when diagnosing hypertension in those individuals suffering from anxiety and/or acute severe pain on presentation.