A NEW NONINVASIVE METHOD USING PULSE OXIMETRY FOR THE ASSESSMENT OF ARTERIAL TOE PRESSURE

We evaluated a novel, simple non-invasive method to assess systolic ar terial toe pressures (ATP). It was empolyed in 63 subjects, of which 3 7 had suspected or established lower extremity arterial disease (LEAD) and 26 did not. 48 of the subjects had diabetes and 15 were non-diabe tic. Pulsatile toe blood flow was monitored with a regular pulse oxime ter (Biox 3700(TM), BOC Ohmeda, Helsingborg, Sweden) (POX) with the se nsor on the tip of the great toe. A small blood pressure cuff was plac ed around the proximal part of the toe and was connected to a sphygmom anometer (Tycos(TM), Levimed AB, Hoganas, Sweden). Systolic pressure w as estimated as the cuff pressure at which pulsatile blood flow ceased during cuff inflation. Toe pressure measurement was obtained, in para llel, using the established strain gauge plethysmographic technique. T here was a good concordance between the two methods (linear regression : r=0.93; y=1.1 x x-6.4; y=pressure obtained with the pulse oximeter, x=pressure obtained with strain gauge, in mmHg). However, patients wit h very low systolic toe pressures, <20 mmHg, could not be reproducibly assessed using the POX method. In conclusion, the POX method was foun d to be a simple and reliable method for the estimation of systolic to e pressures, at least for those above the severly ischemic level. It m ay provide an easily accessible and cost-effective means of vascular a ssessment at the bedside, as well as for out-patients.