Hyperbaric Oxygen Therapy for Diabetic Foot Wounds

Abstract

“ One must always hope when one is desperate, and doubt when one hopes .” Gustave Flaubert. Hyperbaric oxygen therapy (HBOT) has been promoted as an effective treatment for diabetic foot wounds, and the first controlled trial for this indication was reported (in Diabetes Care ) over 20 years ago (1). Advocates have suggested that the experimentally demonstrated effects of HBOT on improving wound tissue hypoxia, enhancing perfusion, reducing edema, downregulating inflammatory cytokines, promoting fibroblast proliferation, collagen production, and angiogenesis make it a useful adjunct in clinical practice for “problem wounds,” such as diabetic foot ulcers (2,3). HBOT is also touted for eradicating difficult to treat soft tissue and bone infections by mechanisms that include killing microorganisms, improving leukocyte and macrophage function, and enhancing the effect of antimicrobials (4). If realized clinically, these beneficial effects, although requiring expensive technology, might powerfully reduce the risk of lower-extremity amputation in diabetic patients with foot wounds. Thus, rigorously assessing the clinical effectiveness of HBOT in diabetic foot ulceration is an important enterprise. But, because both patients and clinicians are strongly motivated to avoid the devastating outcome of amputation, there is a high potential for bias in poorly designed trials. Proof of benefit requires properly conducted clinical trials that minimize the possibility that preexisting prejudices will influence the allocation of patients, diligence of foot care, or other key management decisions. Most of the published reports on the effect of HBOT for treating diabetic foot wounds have been case series or nonrandomized trials with major methodological limitations. Although these are a poor source of evidence, the consistency of positive results is noteworthy. More recently, several randomized controlled trials have been conducted. A Cochrane database systematic review published in 2004 concluded, based on results from four such trials, that “HBOT significantly reduced the risk of …