Assessment of noninvasive lower extremity arterial testing versus pulse exam.

Palpation of pedal pulses was compared to noninvasive testing in 100 patients referred to a vascular laboratory. Subjects were 65 +/- 13 (mean +/- s.d.) years old. The right dorsalis pedis (DP) artery served as the reference artery for comparison of Doppler studies with physical examination of the pulses. Absolute Doppler pressures in the right DP were 129 +/- 50 mm Hg. The right ankle:brachial index (ABI) was 0.86 +/- 0.32. There were significant differences in ABI in those with (0.68 +/- 0.28) vs without (0.95 +/- 0.31) claudication in either extremity (p < 0.001). Rest pain was also associated with lower ABI (P < 0.04). Diabetics, hypertensives, claudicants and those with ischemic rest pain were less likely to have palpable pulses (P < 0.035). With right DP pressure >/= 118 mm Hg, 63 per cent of subjects had a palpable DP pulse, whereas 68 per cent with ABI > 0.82 had a palpable right DP. Of those (n = 35) with a right DP pressure < 118 mm Hg, only 6 per cent (n = 2) had a palpable pulse, whereas 5 per cent (2/40) with ABI </= 0.82 had palpable DP pulses. Based on these findings, it was predicted that a pulse would likely not be palpable in the left DP with a pressure < 118 mm Hg or with AB </= 0.82. The prediction based on systolic ankle pressures was correct, with 66 per cent sensitivity and 91 per cent specificity. The predication that a left DP pulse would not be palpable with AB </= 0.82 was more accurate (78% sensitive, 97% specific). Presence of a palpable DP pulse suggests the presence of a Doppler pressure >/= 188 mm Hg and ABI > 0.82. The range of ankle pressures with palpable right DP pulses was 64-220 mm Hg, whereas the range with nonpalpable DP was 42-300 mm Hg. Given the frequent disparity of pulse exam and ankle pressures, noninvasive Doppler testing may be necessary for many patients to accurately assess the vascular status of the leg.