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.

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.