TRANSCUTANEOUS OXYGEN (TCPO2) ESTIMATES PROBABILITY OF HEALING IN THEISCHEMIC EXTREMITY

The severity of arterial ischemia is a major variable affecting healin g of extremity wounds. By relating risk of failure to severity of isch emia, the probability of wound healing may be stratified along with as sessment of general medical risks. Transcutaneous oxygen tension (TcPO 2) arterial segmental pressure (ASP), and arterial segmental indices ( ASI) were obtained in 204 ischemic lower extremity sites; 63% of the s ites were in patients with diabetes mellitus (DRI), 11% in patients wi th chronic renal failure (CRF), and 37% in patients with neither DM no r CRF (ND). Wounds included 126 amputations and 78 gangrenous ulcerati ons of the foot or toes. Healing (n = 112) was defined as complete wou nd closure, without regard to the time required. Failure (n = 92) was defined by the requirement for either arterial reconstruction (n = 45) or proximal amputation (n = 47). Stepwise multiple regression analysi s was used to assess the relative contribution of each measurement and to predict the probability of healing; TcPO2 was superior to ASP and ASI in all categories. TcPO2 was the only test meeting the P < 0.05 en try criteria modeled by the regression. An accuracy of 83% was achieve d. However, when each test was evaluated by univariate analysis, ASP a nd ASI did meet the criteria for the ND group. However, the accuracy w as 68 and 72%, respectively. Predictive accuracy of TcPO2 was unaffect ed by DM or CBF. ASP and ASI were satisfactory in the ND group, althou gh of slightly reduced accuracy. ASP and ASI were misleading and inacc urate in DM and CRF. Thus, of the noninvasive tests, TcPO2 alone is su fficient for objective risk stratification of arterial ischemia in the lower extremity. (C) 1996 Academic Press, Inc.