Relationship between ulcer healing after hyperbaric oxygen therapy and transcutaneous oximetry, toe blood pressure and ankle-brachial index in patients with diabetes and chronic foot ulcers.

ABSTRACT

AIMS/HYPOTHESIS: The randomised, double-blind, placebo-controlled Hyperbaric Oxygen Therapy (HBOT) in Diabetic Patients with Chronic Foot Ulcers (HODFU) study showed beneficial effect of HBOT. As this treatment is expensive and time-consuming, being able to select patients for therapy would be very useful. The aim of this study was to evaluate whether circulatory variables could help in predicting outcome of HBOT. METHODS: All HODFU study participants who completed therapy, predefined as receiving at least 36 out of 40 scheduled HBOT/placebo sessions, were included in this study (n = 75). Baseline transcutaneous oximetry (TcPO2), toe blood pressure (TBP) and ankle-brachial index (ABI) were measured. Ulcer healing rate was registered at the 9-month follow-up visit. An ulcer was considered healed when it was completely epithelialised and remained so at the 12-month follow-up. RESULTS: In the HBOT group TcPO2 were significantly lower for patients whose ulcer did not heal as compared with those whose ulcers healed. A significantly increased healing frequency was seen with increasing TcPO(2) levels in the HBOT group (TcPO2/healing rate <25 mmHg/0%; 26-50 mmHg/50%; 51-75 mmHg/73%; and >75 mmHg/100%). No statistically significant relation between the level of TBP or ABI and healing frequency was seen. CONCLUSIONS/INTERPRETATION: Our results indicate that TcPO2 in contrast to ABI and TBP correlates to ulcer healing following HBOT. We suggest HBOT as a feasible adjunctive treatment modality in diabetic patients with chronic non-healing foot ulcers when basal TcPO2 at the dorsum of the foot is above 25 mmHg. TRIAL REGISTRATION NCT00953186 FUNDING: Mrs Thelma Zoegas Foundation and Faculty of Medicine, Lund University.