Undersea and Hyperbaric Medical Society
RE: Hyperbaric Oxygen (HBO) Therapy (Section C, Topical Oxygen) (1st Recon) (00060R)
The Undersea and Hyperbaric Medical Society (UHMS) is the specialty society for physicians practicing Undersea and Hyperbaric Medicine (UHM). UHM is recognized by the American Board of Medical Specialties (ABMS) as a subspecialty of both Emergency Medicine and Preventive Medicine. We appreciate the opportunity to comment on the reconsideration of Section C of this NCD pertaining to topical oxygen.
The UHMS agrees that topical oxygen of any type does not meet the definition of hyperbaric oxygen therapy. Also, its clinical efficacy has not been established. Any method of administering oxygen that does not meet the definition of hyperbaric oxygen therapy cannot be considered hyperbaric oxygen. Therefore, we concur with the current CMS policy that no Medicare reimbursement may be made for topical application of oxygen using the codes reserved for hyperbaric oxygen therapy.
The company EO2 asserts that its continuous flow topical oxygen device represents an entirely separate type of topical oxygen therapy than the topical oxygen devices which refer to themselves as “topical hyperbaric oxygen therapy.” EO2 is requesting that “continuous diffusion of oxygen” (CDO) be removed from NCD 20.29 because it asserts that CDO is not a “topical hyperbaric chamber for the extremities.” EO2 requests that a separate NCD be developed to address the use of CDO.
The UHMS has no opinion regarding whether substantive differences exist between the two methods of topical oxygen administration described above. While the UHMS acknowledges that topical oxygen may be beneficial to wound healing, the UHMS does not find the scientific rationale for topical oxygen as presented by EO2 in its letter scientifically accurate. A critical review of the supporting evidence would be required to determine the value of any form of topical oxygen for wound healing. The UHMS supports the development of an NCD to address all forms of topical oxygen therapy for wounds, in conjunction with a review of the scientific evidence.
We strongly assert that it is physiologically impossible for a treatment called “topical hyperbaric oxygen” to even exist. A patient can be treated with topical oxygen, but not topical hyperbaric oxygen. To administer hyperbaric oxygen therapy (HBOT), the patient’s entire body must be placed into a pressure vessel in which the ambient pressure is increased to between 1.5 and 3.0 atmospheres absolute (ATA) while the patient breathes 100% oxygen. While respiring oxygen at 2 ATA, a patient will have an arterial oxygen tension of 1000 mmHg and a muscle oxygen tension over 200 mmHg (2). While breathing oxygen at 3 ATA, the amount of oxygen dissolved in the blood plasma is sufficient to sustain life in the absence of circulating hemoglobin, hence the use of HBOT for acute blood loss anemia. During hyperbaric oxygen therapy, plasma dissolved oxygen is available to all tissues (e.g. brain, bone, muscle and skin). In other words, by definition, hyperbaric oxygen treatment cannot be provided TOPICALLY.
During topical oxygen treatment, some area of the body is placed inside a bag or container filled with oxygen, or oxygen is allowed to flow continuously over the surface of a wound. The oxygen pressure achieved over that region of the body may be a fraction greater than that of sea level, but only to a portion of the body. Assuming no barrier to oxygen diffusion (e.g. necrotic tissue), a small amount of oxygen can diffuse, at most, 2 mm from the surface of the wound. It does not fall within the definition of “hyperbaric oxygen therapy” in which the entire body is exposed to a pressure of oxygen greater than 1.5 ATA.
No one would suggest that a patient who is hypoxic could be treated with topical oxygen (e.g. applying oxygen to the skin) rather than being provided oxygen to BREATHE. However, when wound healing studies of hyperbaric oxygen therapy are co-opted to support the use of topical oxygen therapy, the implication is that the oxygen’s effect on the body is the same whether one breathes it or whether it is topically applied. This assertion is without scientific merit. In fact, the salutary effects of HBOT in wound healing are not limited to the reversal of tissue hypoxia and include the mitigation of ischemia reperfusion injury and the induction of cytokines. These effects of HBOT result from its systemic administration and cannot be achieved via topical administration as far as we currently know. A review article by Thom provides insight into the protean and well elucidated effects of HBOT as a result of exhaustive in vitro and in vivo research (1).
The limited data available on topical oxygen therapy are insufficient to suggest that its mechanisms of action is the same as that of hyperbaric oxygen therapy. Unfortunately, the manufacturers of various topical oxygen devices have linked their devices to hyperbaric oxygen therapy in an effort to extrapolate to topical oxygen the favorable data pertaining to hyperbaric oxygen.
Sadly, the use of the term “topical hyperbaric oxygen” has confused even some wound healing experts. In 2012, a Canadian Advisory Group attempted to use a Delphi process to create guidelines for the use of topical oxygen. However, the use of the term “topical hyperbaric oxygen” and the comingling of topical oxygen and hyperbaric oxygen references caused them to misstate FDA regulatory standards, misinterpret scientific data and misrepresent the risk vs. benefit profile of the two treatments. The muddle created by the Orsted “guidelines” should serve as a cautionary tale for CMS to ensure that for this review, only publications actually pertaining to topical oxygen effects on wound healing are evaluated. (2)
Of even more concern are the findings of the OIG, as reported in their October 2000 publication, “HYPERBARIC OXYGEN THERAPY Its Use and Appropriateness” (OEI 06-99-00090) available at: https://oig.hhs.gov/oei/reports/oei-06-99-00090.pdf. The OIG investigated improper payments for hyperbaric oxygen therapy and determined that one contributing factor was the billing of topical oxygen therapy as hyperbaric oxygen therapy. In the OIG report, great pains were taken to explain the difference between topical oxygen and hyperbaric oxygen therapy. Since at least 2000, the UHMS has urged the FDA, CMS and all federal agencies to stop using the inaccurate term “topical hyperbaric oxygen” because (aside from its physiological impossibility), the confusion thus created might lead to improper billing.
Detailed information regarding the differences between HBOT and topical oxygen are discussed in the UHMS position statement on topical oxygen, available at: http://archive.rubicon-foundation.org/xmlui/bitstream/handle/123456789/5009/16119307.pdf?sequence=1
Thus, the UHMS has the following comments regarding the request for the reconsideration of Section C of NCD 20.29 pertaining to topical oxygen.
- The UHMS agrees that topical oxygen of any type does not meet the definition of hyperbaric oxygen therapy. Any method of administering oxygen that does not meet the definition of hyperbaric oxygen therapy cannot be considered hyperbaric oxygen. Therefore, no Medicare reimbursement may be made for topical application of oxygen using the codes reserved for hyperbaric oxygen therapy.
- No form of topical oxygen therapy should be referred to as “topical hyperbaric oxygen” because not only is it physiologically impossible to provide hyperbaric oxygen topically, but the use of this deceptive term has led to improper billing.
- Should CMS create a separate NCD for the form of topical oxygen therapy called “continuous diffusion of oxygen” (CDO), then we believe all forms of topical oxygen therapy should be included in this NCD regardless of the device used.
- At this time, we are not aware of sufficient evidence to support the assertion that one form of topical oxygen is substantively different from another, but CMS would need to initiate a technology assessment to determine this.
- We strongly urge CMS not to allow studies of actual hyperbaric oxygen therapy to be co-opted to support arguments for the clinical benefit topical oxygen therapy by any device.