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.