Hyperbaric oxygen fails to improve wound healing or prevent amputation

Hyperbaric oxygen therapy didn't improve the likelihood that a wound would heal or prevent amputation in diabetes patients compared to other conventional therapies, a new study found.

In a longitudinal observational study, researchers followed 6,259 patients who had diabetes, adequate lower-extremity arterial flow as determined by a clinician, and a wound on the plantar foot, hindfoot, midfoot or forefoot. Patients also experienced failure to heal during the first four weeks of wound center care and didn't see a decrease in wound size by at least 40% during that time. Eighty-three wound care centers in 31 states provided data for the study from November 2005 to May 2011.

Researchers compared the effectiveness of hyperbaric oxygen with that of other conventional therapies. The outcomes—healed wound and lower-extremity amputation—were assessed 16 weeks after a subject became eligible for the study or 20 weeks after enrollment at a wound care center. Propensity scores were used to determine the likelihood that an individual was selected to receive hyperbaric oxygen. Results were published online Feb. 19 by Diabetes Care.

Hyperbaric oxygen was administered to 12.7% of subjects, most often to a depth of 2.0 atm (88.5% of treatments) five days per week (88%) and for 90-minute sessions (99.5%). In propensity analysis, subjects who received hyperbaric oxygen were less likely to have healing of their foot ulcer (hazard ratio [HR], 0.68; 95% CI, 0.63 to 0.73) and more likely to have amputation (HR, 2.37; 95% CI, 1.84 to 3.04) than those who didn't have this therapy. Additional analyses, aimed at assessing the robustness of results to confounding, also found that hyperbaric oxygen didn't improve the likelihood that a wound would heal or decrease the likelihood of amputation.

Indeed, using multiple analytic approaches, the study found that patients who received hyperbaric oxygen were 1.5 to three times more likely to have an amputation than those who didn't receive hyperbaric oxygen and were 1.2 to three times less likely to heal a foot ulcer, researchers said. About a third of subjects they studied who got hyperbaric oxygen received more than the recommended maximum of 40 treatments, they noted. The authors speculated that hyperbaric oxygen may only enhance a specific aspect of wound repair and may be part of the answer rather than a therapy that should be used until a wound fully heals. The authors concluded by calling for a randomized, controlled trial to help answer this question.