Skin Perfusion Pressure is a Useful Tool for Evaluating Outcome of Ischemic Foot Ulcers with Conservative Therapy

This study intended to confirm whether skin perfusion pressure (SPP) could predict the outcome of ischemic wound healing.

Sixty-two limbs in 53 patients with conservative therapy were enrolled in this study. A SPP value of 40 mmHg was adopted as the criterion for making clinical decisions. The outcome one month after SPP measurement was classified as "improved" (diameter of ulcer decreased ≥ 20% or demarcation of gangrene became well defined) or "no change or worse" (others), and the fate of wound was classified as "healed" or "not healed". The evaluated influential factors on the outcome at one month included age, sex, presence of arteriosclerosis obliterans, collagen disease, hypertension, diabetes mellitus, hemodialysis, wound infection, wound management, and SPP ≥ 40 mmHg.

Using a criterion of SPP ≥ 40 mmHg, the outcome at one month could be predicted with a sensitivity: of 75.0%, a specificity: of 82.6%, and an accuracy: of 80.6%. The receiver operating characteristic curve indicated our criterion to be appropriate. Logistic regression analysis showed SPP ≥ 40 mmHg to be an independent factor (P < 0.0001) with the odds ratio of 14.2 (95% CI 3.6-55.8).

SPP, using a cutoff value of 40 mmHg, can predict the ischemic wound healing with conservative therapy.