An evaluation of the Avionics Pressurometer III 1978 at home and in hospital

The Avionics Pressurometer III is the only noninvasive indirect ambulatory blood pressure system which provides 24-h blood pressure measurements, but it has been subjected to limited evaluation. We report a critical evaluation comparing it to simultaneous intra-arterial blood pressures both at home and at hospital as well as during standardized exercise. Comparisons with simultaneous indirect methods were also made. Twenty-two hypertensives undergoing intra-arterial ambulatory blood pressure monitoring wore the two recorders for one day. The mean difference (standard deviation SD) for intra-arterial blood pressure--Avionics blood pressure was 2 (SD 8.6)/-14 (SD 10.3) mmHg at home and -3 (SD 15.4)/-11 (SD 12.3) mmHg at hospital. At the end of exercise the figures for the same comparison were -7 (SD 16)/0 (SD 15.6) mmHg. In general the agreement between intra-arterial and Avionics pressurometer recordings was closer for systolic than for diastolic blood pressures but there was wide variation for individuals as shown by the standard deviations about the mean difference. We did not use the recorder at night as patients complained that the noise kept them awake and so night-time blood pressures were not attainable. We do not think the recorder performed satisfactorily during physical exertion, and in view of its expense, this recorder is of limited potential value in supplying accurate information.