Evaluation of a new screening method for detecting peripheral arterial disease in a primary health care population of patients with diabetes mellitus.

Abstract

To compare the ability to detect peripheral arterial disease between the traditional ankle Doppler technique for measuring ankle blood pressure and a new pulse oximetric method for measuring systolic toe pressure, in an unselected primary health care population with diabetes mellitus. The total population with the diagnosis diabetes mellitus in two primary health care districts was studied. The population was investigated by means of pulse palpation, ankle Doppler pressure, systolic toe pressure using a pulse oximetric method, arm blood pressures, neuropathy screening and laboratory tests. A total of 126 patients were included in the study. In these patients, 250 extremities were investigated. Systolic ankle Doppler pressure and ankle/arm pressure indices were found to be significantly higher than the pressures and indices achieved with the pulse oximetric method (158 +/- 44 vs. 117 +/- 33 mmHg, P < 0.0001, and 1.02 +/- 0.24 vs. 0.76 +/- 0.22, P < 0.0001). Thirty-one extremities with a systolic toe pressure < 80 mmHg were found. Twenty-one of these lacked a palpable pulse in the dorsal pedial or posterior tibial artery. The pulse oximetric method gave significantly more pathological indices (Doppler index < or = 0.8, pulse oximeter index < or = 0.6) (Doppler 36/250, pulse oximeter 58/250, P = 0.003). However, the Doppler method gave significantly more indices above 1.3 compared with the pulse oximetric method (33/250 vs. 2/250, P = 0.003). This study demonstrates that ankle Doppler pressure measurements overestimate peripheral arterial pressure in a typical primary health care population. In the screening situation, this new pulse oximetric toe pressure method seems to be valuable since it can be performed in out-patient clinics and handle large numbers of patients in a short time and avoid the problem of media sclerosis.