Point-Counterpoint: HBOT: Is It Worthwhile For DFUs?
Ironically, CMS’s decision to pay for outpatient-only use of HBOT may have resulted in a double whammy of excessive treatment for patients who would not benefit and denial of treatment for patients who would benefit. In clinical practice, I have been frustrated more often than not that payment policies prevent me from treating the hospitalized patient with a gangrenous foot that requires incision and drainage, or partial foot amputation, such as a transmetatarsal amputation or ray resection. Postoperative transmetatarsal amputation failures are high in patients with diabetes and ischemia, suggesting that this would be an ideal population to use HBOT for limb salvage. However, this would not be considered an appropriate patient population using CMS guidelines.41,42 This leaves physicians trying to find alternative diagnoses that they can use to justify HBOT rather than letting their patients go untreated.
Does this mean that we should only use HBOT on admitted patients who are getting aggressive debridement? The answer is no. Recent double-blinded RCTs using the CMS guidelines that dictate a waiting period before HBOT therapy showed an increased percentage of healed patients in the HBOT group and one study showed that for every four patients treated with HBOT, physicians averted one non-healing ulcer.1,7
Further support for the use of HBOT for diabetic foot ulcers comes from meta-analyses published in non-hyperbaric journals. The Cochrane Report concluded that “HBOT seems to improve the chance of healing diabetes-related foot ulcers and may reduce the number of major amputations in people with diabetes who have chronic foot ulcers.”23 The Infectious Diseases Society of America (IDSA) gave HBOT a strong recommendation with moderate evidence with regard to wound healing but not for resolving infection.43 All of this has led some critics of HBOT to reconsider their stance.44
Determining The Selection Criteria For HBOT
Given the evidence demonstrating that HBOT is an efficacious treatment, the biggest hurdle is determining the proper selection criteria for patients for whom HBOT will be of benefit. Studies of large groups of patients receiving HBOT have shown this is easier said than done. Transcutaneous oxygen monitoring (TCOM) has been a useful tool in predicting success or failure with HBOT, but baseline TCOM is not as useful as measuring TCOM response to hyperbaric exposure.12,13,20,45,46 Other factors that have been linked to outcome in DFUs are renal failure, pack-year smoking history and the number of HBOT sessions completed although none of these can reliably predict who will respond and who will not.10,12
Future research needs to elucidate screening criteria that will help segregate patients into three groups: those who will reliably heal without HBOT; those who are unlikely to heal with HBOT; and those who remain candidates for HBOT. Until then, a combination of clinical experience, transcutaneous oximetry and incorporation into a comprehensive wound care program remains the best option with regard to patient selection for HBOT.
Dr. Huang is the Medical Director of Wound Healing and Hyperbaric Medicine at Adventist Medical Center in Portland, Ore. He is an Affiliate Assistant Professor of Emergency Medicine at Oregon Health and Science University in Portland, Ore. He is also an Assistant Clinical Professor of Emergency Medicine at the Western University of Health Sciences in Pomona, Calif.