The correlation of ankle oscillometric blood pressures and segmental pulse volumes to Doppler systolic pressures in arterial occlusive disease.

Abstract

This study was designed to evaluate the accuracy and failure rates of automatically collected oscillometric ankle systolic pressures (Psys) and pulse volumes (Pvol) using a new algorithm as compared with Psys obtained by standard manual Doppler-and-cuff technique. One hundred ten consecutive patients at a vascular laboratory had brachial and ankle Psys measured with the two methods. Pvol at or near the mean arterial pressure was also obtained automatically by the oscillometric device. Both methods showed a 6.6% failure rate when measuring Psys at the ankle. Oscillometric Psys measurement was possible when Doppler Psys failed as a result of nonoccluding arteries. No difference was found between the two methods in occluding limbs with ankle-brachial indexes of 1.30 or more. Sequential brachial Psys values had a mean difference (Doppler-oscillometric) or 2 +/- 10.9 mm Hg and a correlation coefficient (r) of 0.92. Measurements at the ankle had a mean difference of -8.4 +/- 16.8 mm Hg and r = 0.90. These differences were not statistically significant. Mean arterial pressure Pvol recorded at the ankle also correlated with ankle Doppler Psys (r = 0.71) and showed a 1.9% failure rate. Both automatic oscillometric plethysmographic Psys and Pvol at the ankle are shown to correlate well with Doppler-and-cuff Psys in patients with vascular disease. Oscillometric measurements can replace Doppler measurements in most clinical situations.