A Comparison of Two Ambulatory Blood Pressure Monitors, the Del Mar Avionics Pressurometer IV and the Spacelabs 90202

The purpose of this study was to evaluate the accuracy of two noninvasive ambulatory blood pressure (BP) monitors, the new Del Mar Avionics Pressurometer IV (PIV) and the second generation Spacelabs 90202. Two sets of comparisons were made between two trained observers and the monitors on 17 normotensive and 28 hypertensive subjects. The result of the first comparison showed that the average difference between observers and the PIV was 1.2/-2.2 mm Hg for systolic and diastolic BP. Comparisons of both monitors to the observers showed differences of 0.9/1.0 mm Hg for the PIV and 0.3/0.8 mm Hg for the 90202 (systolic/diastolic). Correlations between the average observer reading and the monitors over both sets of comparisons ranged from 0.90 (diastolic 90202 vs observer) to 0.98 (systolic PIV vs observer). The percentage of readings within 5 mm Hg between observer and monitor over all comparisons ranged from a low of 68% (90202, systolic and diastolic) to a high of 83% (PIV, diastolic). In general, both devices are satisfactory and reliable machines for ambulatory BP monitoring, but each has a slightly different bias compared to auscultatory readings.