The inaccuracy of automatic devices taking postural measurements in the emergency department

Abstract

Automatic devices are used to take postural blood pressures in the emergency department despite research proving their inaccuracy in taking single blood pressures. This study assessed the accuracy of an automatic device compared with a manual aneroid reference standard for determining orthostatic hypotension and postural drops at triage. Supine and standing blood pressures were taken with an automatic and a manual device in a sequential and random order, and postural drops were calculated. The manual device indicated 10/150 emergency department patients had orthostatic hypotension (7%) and the automatic device detected this with a sensitivity of 30% and a specificity of 91%. The automatic-manual differences were clinically significant in 13% of systolic drops and 37% of diastolic drops. Findings suggest that automatic devices cannot reliably detect or rule out orthostatic hypotension, indicating that triage nurses need to use manual devices to take accurate postural blood pressures for optimal patient care.