The Impact of Adjunct Hyperbaric Oxygen Therapy on Healing Diabetic Foot Ulcers: A Retrospective Case-Control Study at a Tertiary Care Center.

BACKGROUND: A reduced oxygen supply to diabetic foot ulcers slows down wound healing, as it affects angiogenesis, reepithelialization, and extracellular matrix formation. A compromised blood supply impairs oxygen delivery to the wound, creating a hypoxic environment around it. Hyperbaric oxygen therapy (HBOT) increases the concentration of dissolved oxygen in the plasma. It compensates for the existing hypoxia and promotes wound healing. HBOT promotes neovascularization and matrix formation, decreases inflammation, and increases reactive oxygen free radicals, which can kill bacteria. Moreover, HBOT overwhelms the enzymes that reduce free radical production. Adverse effects are very rare when patients are carefully screened before treatment. However, HBOT cannot maintain the increased oxygen concentration. Therefore, a discussion of the overall benefits of HBOT for wound healing is warranted. This study aimed to evaluate the effect of HBOT on the healing of diabetic foot ulcers in terms of the time taken for complete wound healing. METHODS: A retrospective case-control study was conducted at a tertiary care center on 235 inpatients selected according to defined inclusion and exclusion criteria. The patients' clinical parameters influencing wound healing, such as age, HbA1c levels, serum albumin, hemoglobin, ankle-brachial index, and comorbid conditions, were recorded. The severity of wounds according to the University of Texas wound classification system was recorded. Patients who received standard-of-care treatment were included in the control group. Patients who received HBOT as an adjunct therapy along with standard of care treatment were included in the experimental group. All patients in both groups underwent necessary surgical and vascular interventions. Wound follow-up was performed for six months, and complete wound healing was the primary endpoint. RESULTS: Logistic regression showed that the HBOT group patients had improved wound healing (odds ratio (OR) = 2.84) compared with the control group patients. The logistic regression analysis indicated that the HBOT group was associated with a significant improvement in wound healing after accounting for the severity of diabetic foot ulcers. HBOT was predominantly used for patients with worse baseline ulcers, and the median time to healing was significantly longer in the HBOT group than in the control group. Potential confounders of the association between HBOT and wound healing were identified using a Bayesian network. Even after adjusting for potential confounders, HBOT showed a favorable trend (OR = 2.32), although it did not reach statistical significance. CONCLUSION: This study demonstrates a positive correlation between HBOT and the healing of diabetic foot ulcers. HBOT, when used as an adjunct to standard-of-care treatment, significantly shortened the time to healing in University of Texas grade 1 ulcers. Further research in this area may justify considering HBOT as a standard-of-care treatment for diabetic foot ulcers.