Hyperbaric Oxygen Does Not Help Chronic Diabetic Foot Ulcers

Marlene Busko

January 19, 2016

Among 103 diabetic patients with a nonhealing foot ulcer who received standard care, those who additionally received hyperbaric-oxygen therapy were just as likely to need an amputation as patients who also received sham therapy, in a new randomized controlled trial.

Moreover, adjuvant hyperbaric-oxygen therapy did not improve wound healing compared with added sham therapy, in this study by Ludwik Fedorko, MD, associate professor of anesthesiology and pain management at the University of Toronto, Ontario, and colleagues, which was published online January 6, 2016 in Diabetes Care.

"Because our sample is…very small for an epidemiological study and [the confidence interval is large], we cannot exclude that there is [an as-yet unidentified] subpopulation of diabetic patients [with chronic foot ulcers] who might benefit from hyperbaric-oxygen [therapy]," Dr Fedorko told Medscape Medical News.

"However, until such a subset can be confirmed to exist in future studies, we cannot recommend the use of adjuvant [hyperbaric-oxygen therapy] for reducing indications for amputation or for facilitating healing in this patient population," he and his colleagues conclude.

Debate About Hyperbaric-Oxygen Therapy

Dr Fedorko had presented preliminary findings from the current study in a debate at the American Diabetes Association 2015, where he argued against the case for hyperbaric-oxygen treatment for diabetic foot ulcers and pointed out flaws in the two other published randomized trials of this therapy for this patient population, by Abidia et al (Eur J Vasc Endovasc Surg. 2003;205:513-518) and Löndahl et al (Diabetes Care. 2010;33:998-1003).

Both of those studies reported surprisingly low rates of healing in the sham groups, and the sham treatment was not benign, which may explain why the studies showed "an apparent benefit" from hyperbaric-oxygen therapy, Dr Fedorko speculated.

On the other hand, the current study findings corroborate those in a retrospective review by Margolis et al of 793 patients who received hyperbaric-oxygen therapy vs 5466 patients who received standard care (Diabetes Care. 2013;36:1961-1966).

These two studies now show that "if you apply proper wound care, there's absolutely no benefit to adding hyperbaric-oxygen therapy," according to Dr Fedorko.

Does Breathing Normal Oxygen Heal Foot Ulcers?

In their study, Dr Fedorko and colleagues analyzed data from 103 diabetic patients who were seen at their center between 2009 and 2012 and had Wagner grade 2 to 4 foot lesions (where 0 = no ulcer and 5 = ulcer requiring amputation) that had had persisted for at least a month despite wound care.

The patients were randomized to receive adjunctive hyperbaric-oxygen treatment (49 patients) or sham treatment (54 patients), given 5 days a week for 6 weeks.

In each of the 30 sessions, patients in the study-treatment group breathed oxygen at 244-kPa pressure and patients in the sham group breathed air at 125-kPa of pressure for 90 minutes.

All patients had weekly clinical assessments for 12 weeks and received infection control, debridement, prescriptions for offloading devices (eg, removable cast walker), and advanced wound-care dressings.

The patients had a mean age of 61. There were more men in the sham group than in the hyperbaric-oxygen group (70% vs 63%); fewer patients in the sham group had type 1 diabetes (one in 54 vs six in 49 in the hyperbaric group), and they had diabetes for fewer years (12 vs 19).

At the 12-week study end, 11 of 49 patients in the hyperbaric-oxygen group vs 13 of 54 patients in the sham group were deemed to need a major, below-the-knee amputation (odds ratio [OR], 0.91; P = .846).

Similarly, 14 of 49 patients in the hyperbaric-oxygen group vs 13 of 54 patients in the sham group met the criteria for a minor amputation at the level of the foot (OR, 1.26; P = .605).

Moreover, there was no significant between-group difference in wound size, wound assessment (Bates-Jensen score), or wound classification (Wagner score). Ten patients (20%) in the hyperbaric-oxygen group vs 12 patients (22%) in the sham-treatment group had healed wounds (Wagner score of 0 or 1; OR, 0.90; P = .823).

There is good, level 1 evidence that hyperbaric-oxygen therapy improves wound healing in patients with wounds from radiation therapy for cancer, Dr Fedorko noted.

But those wounds are very different from foot ulcers in patients with diabetes and neuropathy, and "there is no evidence at this moment that this treatment is effective for diabetic patients," he concluded.

The study was funded by an unconditional research grant from the Ontario Ministry of Health and Long-Term Care. The authors have no relevant financial relationships.

Diabetes Care. Published online January 6, 2016. Abstract


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