Clinical reliability and utility of skin perfusion pressure measurement in ischemic limbs--comparison with other noninvasive diagnostic methods

Abstract

Purpose: We studied whether the measurement of skin perfusion pressure (SPP) is useful for evaluating ischemic limbs and predicting wound healing.

Methods: Two hundred eleven patients (age range, 45 to 90 years; mean age, 69.6 +/- 9.2 years; 170 men and 41 women), 403 limbs with arteriosclerosis obliterans, were included in this study. Half of the patients had diabetes or were receiving dialysis or both.

Results: Significant correlations were found between SPP and ankle blood pressure (ABP), SPP and toe blood pressure (TBP), and SPP and the transcutaneous oxygen pressure (tcPO2) (P < .0001, r = 0.75; P < .0001, r = 0.85; P < .0001, r = 0.62; respectively). In 94 limbs with ulcer or gangrene, wound healing was predicted by the SPP. The mean SPP (mean +/- SD) in the healed-wound group (25 limbs, 48 +/- 20 mm Hg) was greater than that in the unhealed-wound group (69 limbs, 23 +/- 11 mm Hg) (P <.001). According to the receiver operating characteristic (ROC) curve, the cut-off value of SPP was 40 mm Hg (sensitivity, 72%; specificity, 88%). Furthermore, we studied whether the combination of SPP and another measurement could predict wound healing more accurately than could any single variable. There was a strong correlation between SPP, TBP, and the healing rate (P < .001, r = 0.69) and healing could be accurately predicted if the SPP was greater than 40 mm Hg and if the TBP was greater than 30 mm Hg.

Conclusions: Our results suggest that measurement of SPP is an objective method for assessing the severity of peripheral arterial disease or for predicting wound healing.