Comparison of three blood pressure methods used for determining ankle/brachial index in patients with intermittent claudication.

The standard noninvasive test to assess the severity of peripheral arterial occlusive disease (PAOD) is the ankle/brachial systolic blood pressure index (ABI). While ankle systolic blood pressure is obtained by the Doppler ultrasound technique, brachial systolic blood pressure can be obtained by the Doppler, auscultatory, or oscillometric (Dinamap 1846 SX) methods. The purpose was to determine whether the three methods yielded similar brachial systolic blood pressure values, and consequently similar ABI values, in PAOD patients with intermittent claudication. Fifty patients who had a history of intermittent claudication of 2.3 +/- 2.0 blocks for a duration of 5.7 +/- 5.8 years were recruited. Following 10 minutes of supine rest, brachial systolic blood pressure was measured in the right arm by the three techniques in a randomized order, and ankle systolic blood pressure (87.3 +/- 28.9 mmHg) was measured in the more symptomatic leg with the Doppler technique. Brachial systolic blood pressure was not significantly different (p=0.954) among the Doppler (128.5 +/- 18.4 mmHg), auscultatory (128.4 +/- 17.4 mmHg), and oscillometric (128.2 +/- 17.1 mmHg) methods. Corresponding ABI values also were similar (p=0.922) among the three respective methods (0.68 +/- 0.22, 0.68 +/- 0.22, and 0.68 +/- 0.21), indicating that ABI did not vary according to the technique used to obtain brachial systolic blood pressure. It is concluded that the accuracy of determining ABI in PAOD patients with intermittent claudication was minimally affected by the method chosen to obtain brachial systolic blood pressure.