Will A New Study Change The Way Physicians Use HBOT For Patients With DFUs?

Evidence-based medicine founded on high-level research occasionally challenges our existing paradigms, resulting in the ongoing evolution of medicine. To quote William Osler, "What is the student but a lover courting a fickle mistress who ever eludes his grasp?"

A recent study by Fedorko and colleagues published online for Diabetes Care is such an example.¹ I believe this article will have profound effects on the use of hyperbaric oxygen therapy (HBOT) for the treatment of diabetic foot ulcers (DFUs).

What type of effect? Remember what happened when the study by Buchbinder and coworkers came out in the Journal of the American Medical Association in 2002 on the use of extracorporeal shockwave therapy (ESWT) for plantar fasciitis?² Shockwave went from a covered procedure to a non-covered procedure in a blink of an eye despite several other positive articles on ESWT.

The study by Fedorko and colleagues was a double-blind, placebo-controlled clinical trial of HBOT in patients with chronic DFUs of at least four weeks in duration who were receiving comprehensive wound care.¹ The primary study outcome metric the authors examined was the reduction of amputation indications with a secondary outcome measure of wound healing. The study consisted of two groups with one group receiving HBOT (49 patients) and the other group getting sham HBOT (54 patients). The HBOT group received treatment five days per week for six weeks for a total of 30 sessions. Treatment consisted of 90 minutes of oxygen therapy at 244 kPa with five-minute intervals of breathing oxygen every 30 minutes. The sham group breathed air at ~125 kPa of pressure on the same schedule. Researchers also employed standard wound care per Lipsky and colleagues for both groups over the 12 weeks of the study.³

A vascular surgeon evaluated the patients in both groups for amputation (below-knee or transmetatarsal levels) based on four criteria.¹

1. Lack of significant progress in wound healing over the follow-up period, which indicated ongoing risk of severe systemic infection related to the wound


2. Persistent deep infection involving bone and tendons (antibiotics required, hospitalization required, pathogen involved)

3. Inability to bear weight on the affected limb

4. Pain causing significant disability

In regard to the secondary outcome measure of wound healing, the study authors reviewed wound measurements and assessed changes in wound assessment scores and wound classification.¹

In the HBOT group, 13 of 54 patients met the results for major amputation criteria whereas 11 of 49 patients met the criteria in the sham group.¹ These findings were not statistically significant between groups. The secondary outcome metric of wound healing also showed no statistically significant difference between the HBOT group (10 patients or 20 percent achieving wound healing) and the sham group (12 patients or 22 percent achieving wound healing).¹

I work at a Healogics wound care center and the basis of the Healogics approach is an evidence-based approach to wound care. There is a strong emphasis on HBOT in our center and all Healogics centers in general. Podiatrists at our center are not allowed to monitor HBOT but in several other wound care clinics around the country, DPMs do monitor HBOT. Monitoring HBOT can be a large part of some podiatry practices, especially for those DPMs who are heavily involved in wound care.

The question becomes will Healogics and other wound care companies either change their fundamental approach to DFUs with regard to HBOT or more likely be forced to change by insurance companies? The expense associated with HBOT and potential adverse effects — in the aforementioned study, the total number of adverse events for the HBOT group was 29 versus 8 for the sham group — place an enormous target on HBOT from an insurance coverage standpoint.¹ With the tightening of the belt on healthcare expenses, to think otherwise would be naïve. 

To quote Fedorko and colleagues, "The current study did not find a significant benefit associated with adjuvant HBOT. A subset of diabetic lower-extremity wounds may benefit from HBOT; however, until such a subset can be confirmed to exist in future studies, we cannot recommend the use of adjuvant HBOT for reducing indications for amputation or for facilitating healing in this patient population."¹

I expect this study to have a profound effect on the use of HBOT for DFUs one way or another. Either we practice evidence-based medicine or, in cases like this when the outcome flies in the face of current paradigm, Osler's "cruel mistress" will force it upon us.

References

1.   Fedorko L, Bowen J, Jones W, et al. Hyperbaric oxygen therapy does not reduce indications for amputation in patients with diabetes with nonhealing ulcers of the lower limb: a prospective, double-blind, randomized controlled clinical trial. Diabetes Care. 2016; epub Jan. 6.

2.   Buchbinder R, Ptasznik R, Gordon J, Buchanan J, Prabaharan V, Forbes A. Ultrasound-guided extracorporeal shock wave therapy for plantar fasciitis. J Am Med Assoc. 2002; 288(11):1364-72.

3.   Lipsky B, Berendt A, Cornia P, et al. 2012 Infectious Diseases Society of America Clinical Practice Guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2012; 54(12):e132-e173.