Transcutaneous oxygen tension measurements in the detection of iliac and femoral arterial disease.

The sensitivity and specificity of the noninvasive measurement of transcutaneous oxygen tension (PtcO2) in detecting the site of vascular disease in either the iliac or superficial femoral arteries is reported herein. Patients presenting with intermittent claudication or ischemic pain at rest were studied to determine the presence or absence of iliac or femoral occlusive disease by assessing the level of PtcO2 measurements at sites above and below the knee. PtcO2 studies were assessed against changes in the arteriogram, the "gold standard" for judging peripheral arterial insufficiency. Using our criteria, PtcO2 measurements above the knee show a sensitivity rate of 86 per cent and a specificity rate of 20 per cent to detect iliac disease. PtcO2 measurements below the knee show a sensitivity rate of 91 per cent and a specificity rate of 33 per cent to detect femoral disease. The accuracy was 69 per cent and 76 per cent, respectively. The user of the test is mainly concerned with the "predictive values" which are functions of the sensitivity, specificity and prevalence of the disease. Transcutaneous oxygen measurements above and below the knee show a very good sensitivity for detecting iliac and femoral disease, indicating that they may well serve as a quick and convenient noninvasive diagnostic procedure.