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Am Fam Physician. 2020;102(8):online

Clinical Question

Is topical oxygen effective in hastening the healing of refractory diabetic foot ulcers?

Bottom Line

Hyperbaric oxygen provided with a device that cycles oxygen from high pressure to low pressure increased the likelihood of complete healing of diabetic foot ulcers when combined with standard dressing and an offloading boot. The study was small, and fewer than one-half (41.7%) of the patients responded after three months of treatment. (Level of Evidence = 1b−)


The investigators enrolled 73 patients with diabetes mellitus who had been recruited from wound centers. The patients had full-thickness diabetic foot ulcers between 1 cm2 and 19 cm2 and had been treated for at least four weeks. They were observed for an additional two weeks, treated with dressing and a rocker sole boot, and were enrolled in the study if they did not have at least a 30% decrease in wound area with this treatment. Using concealed allocation, the study patients were treated with a closed chamber device that provided hyperbaric oxygen cycled between 10 mb and 50 mb (Hyperbox) or a sham device that circulated nonpressurized ambient air. Patients used the device 90 minutes each day five times a week. Using intention-to-treat analysis, after 12 weeks of treatment, 41.7% of patients who received oxygen had complete wound healing compared with 13.5% who received sham treatment (P = .01). For patients without total healing, oxygen therapy was discontinued, and usual care was continued for up to one year. By 12 months (nine months after discontinuing hyperbaric oxygen), 56% of patients who received oxygen had complete healing compared with 27% of patients who received sham treatment. Adverse events were reported in both groups; none were related to the device.

Study design: Randomized controlled trial (double-blinded)

Funding source: Industry

Allocation: Concealed

Setting: Outpatient (specialty)

Reference: Frykberg RG, Franks PJ, Edmonds M, et al.; TWO2 Study Group. A multinational, multicenter, randomized, double-blinded, placebo-controlled trial to evaluate the efficacy of cyclical topical wound oxygen (TWO2) therapy in the treatment of chronic diabetic foot ulcers: the TWO2 study. Diabetes Care. 2020;43(3):616–624.

Editor's Note: Dr. Shaughnessy is an assistant medical editor for AFP.

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see Copyright Wiley-Blackwell. Used with permission.

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