Differences in automated and manual blood pressure measurement in hospitalized psychiatric patients.

Few studies have been conducted recently with noncritically ill patients evaluating commonly used automated blood pressure (BP) devices. The purpose of this study was to compare BP values obtained using a manual sphygmomanometer versus an oscillometric automated electronic BP device on an acute care psychiatry unit. A method-comparison design was used, and data were analyzed using the Bland-Altman method. Outliers were removed, resulting in 39 participants for analyses of systolic readings and 41 participants for diastolic readings. Paired t tests revealed a significant difference in manual versus automatic systolic BP readings (p < 0.05). Automated readings averaged 3.9 points higher. No significant differences in diastolic readings (p = 0.72) were found. Care must be taken in using automated or manual BP readings to make important clinical decisions. Based on these findings, a protocol was instituted in an acute care psychiatry unit indicating that BP must be measured manually for patients with medication-hold parameters for BP.