[Are automatic devices suitable for blood pressure determinations?]

Abstract

Four automatic blood pressure recorders (Bosograph II, Bosch EBM 500, Elag BE 237R, and Physiometrics SR-2) were compared with the random zero sphygmomanometer. Since each of the automatic devices was calibrated for phase IV, diastolic blood pressure values were read off at phase IV and not phase V of Korotkow with the random zero sphygmomanometer. Blood pressure measurements were carried out in 80 patients with hypertension and in 20 normotensive healthy subjects. Readings with the automatic recorders and with the random zero sphygmomanometer correlated well in a wide range of systolic and diastolic blood pressure (r = 0.878--0.982, p less than 0.001). However, the automatic values were in most cases significantly lower than those obtained with the random zero device. For Physiometrics SR-2, where two diastolic readings were possible, only the first diastolic values correlated well with phase IV of Korotkow. The second values were significantly lower, with a difference of -11.1 mm Hg, and probably did not reflect the true diastolic blood pressure. These results show that each of the four automatic recorders is suitable for measuring blood pressure. However, with the Physiometrics SR-2, Only the higher diastolic reading should be used. The differences between the four automatic devices were minor and can therefore be ignored.