Background: Chronic wounds are common and present a health problem with significant effect on quality of life. Various pathologies may cause tissue breakdown, including poor blood supply resulting in inadequate oxygenation of the wound bed. Hyperbaric oxygen therapy (HBOT) has been suggested to improve oxygen supply to wounds and therefore improve their healing.
Objectives: To assess the benefits and harms of adjunctive HBOT for treating chronic ulcers of the lower limb.
Search methods: For this first update we searched the Cochrane Wounds Group Specialised Register (searched 12 January 2012); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); Ovid MEDLINE (1950 to January Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, 11 July 2012); Ovid EMBASE (1980 to 2012 Week 01); and EBSCO CINAHL (1982 to 6 January 2012).
Selection criteria: Randomised controlled trials (RCTs) comparing the effect on chronic wound healing of therapeutic regimens which include HBOT with those that exclude HBOT (with or without sham therapy).
Data collection and analysis: Three review authors independently evaluated the risk of bias of the relevant trials using the Cochrane methodology and extracted the data from the included trials. We resolved any disagreement by discussion.
Main results: We included nine trials (471 participants). Eight trials (455 participants) enrolled people with a diabetic foot ulcer: pooled data of three trials with 140 participants showed an increase in the rate of ulcer healing (risk ratio (RR) 5.20, 95% confidence interval (CI) 1.25 to 21.66; P = 0.02) with HBOT at six weeks but this benefit was not evident at longer-term follow-up at one year. There was no statistically significant difference in major amputation rate (pooled data of five trials with 312 participants, RR 0.36, 95% CI 0.11 to 1.18). One trial (16 participants) considered venous ulcers and reported data at six weeks (wound size reduction) and 18 weeks (wound size reduction and number of ulcers healed) and suggested a significant benefit of HBOT in terms of reduction in ulcer area only at six weeks (mean difference (MD) 33.00%, 95% CI 18.97 to 47.03, P < 0.00001). We did not identify any trials that considered arterial and pressure ulcers.
Authors' conclusions: In people with foot ulcers due to diabetes, HBOT significantly improved the ulcers healed in the short term but not the long term and the trials had various flaws in design and/or reporting that means we are not confident in the results. More trials are needed to properly evaluate HBOT in people with chronic wounds; these trials must be adequately powered and designed to minimise all kinds of bias.