Hyperbaric oxygen therapy (HBOT) has garnered attention both in scientific circles and in the popular press.
For example, Jacqueline Laurita, who plays in the reality show Real Housewives of NJ,uses HBOT to treat her autistic son.1 NFL players such as Tim Tebow and Hines Ward routinely use HBOT for healing bumps and bruises after practice.2 Dr. Oz enthusiastically recommends it as a "great longevity tool" that "keeps stem cells healthier so they can repair our bodies."3 HBOT is touted as a wonder chamber for diseases as varied as AIDS/HIV,neurodegenerative conditions, asthma, and autism.
But does it work? And is it safe?
It works for some conditions but not others, according to the U.S. Food and Drug Administration (FDA).4 According to the FDA, HBOT has not been clinically proven to cure or be effective in the treatment of cancer, autism, or diabetes and is not approved for these indications.4 Only 13 uses of HBOT are FDA-approved, including treatment of air or gas embolism, carbon monoxide poisoning, decompression sickness, and thermal burns.
But "patients may incorrectly believe that [HBOT] devices have been proven safe and effective for uses not cleared by FDA," according to Nayan Patel, a biomedical engineer in the FDA's anesthesiology branch.4 Additionally, HBOT has risks that range from mild (eg, sinus pain, ear pressure, painful joints) to serious (eg, paralysis).4
How Does HBOT Work?
A person being treated with HBOT breathes 100 percent O2 while exposed to increased atmospheric pressure.5 The elevated hydrostatic pressure increases partial pressure of gases and reduces the volume of gas-filled spaces.5 Gas volume reduction has "direct relevance to treating pathological conditions in which gas bubbles are present in the body, such as arterial embolism and decompression sickness."5
HBOT also increases growth factors and local wound signaling, while promoting a central stem cell release of endothelial progenitor cells from the bone marrow via nitric oxide pathways.6
HBOT: A Sampling of Research
Although the FDA has not formally approved HBOT for conditions such as autism and diabetes, HBOT has been widely researched for these and other conditions. Findings from clinical trials show HBOT to be a promising intervention in stroke and diabetic foot ulcers, but less promising in autism.
Stroke: Hyperbaric oxygen is an "approved treatment modality for ischemia-reperfusion injury."7 It "maintains the viability of the marginal tissue, reduces the mitochondrial dysfunction, metabolic penumbra, and blocks inflammatory cascades observed in acute stroke."7 Data suggest that it is a "safe and effective treatment option" in the management of acute stroke7 as well as post-stroke symptoms, even in chronic late stages.8
Diabetic Foot Ulcers: HBOT is frequently used as an adjunctive treatment for diabetic hard-to-treat ulcers, improving abnormal low tissue oxygen tension in wound areas.9 HBOT stimulates several phases of wound healing, including infection control and reduction of tissue edema.9
A recent review found the quality of many studies of HBOT in diabetic foot ulcers to be "weak," but noted that "the consistency of positive outcomes is noteworthy, not least because these findings are in concert with data from in vitro and physiological studies supporting the theoretical framework of HBOT reversing hypoxia-induced pathology." The author cited two "well-designed" randomized, double-blind, placebo controlled trials9,10 that "have in recent years put HBOT on firmer ground as treatment for diabetic patients with chronic foot ulcer."9
Autism: Use of HBOT in the treatment of autism is controversial. A small study of 10 children with autism spectrum disorder found that all children who had been treated with HBOT improved by 2 points on the clinician-rated Clinical Global Impression Improvement (CGI-I)11 But another study of 60 autistic children, which compared HBOT to sham treatment, found similar improvements between the two groups.12
A review of 18 studies found that while some uncontrolled and controlled studies suggested that HBO therapy is effective for the treatment of autism, these "promising effects" were not replicated across all studies. The author recommended more "sham-controlled studies with rigorous methodology" to reach evidence-based conclusions.13
The European Committee for Hyperbaric Medicine (ECHM)'s 2010 workshop titled "Controversial Issues in Hyperbaric Oxygen Therapy," which reviewed not only research evidence but also reported from the clinical experiences of specialists and hyperbaric facilities, concluded that the use of HBOT for treatment of autism could not be recommended.14
The field of HBOT "continues to evolve and grow."15 New indications are currently being researched in clinical trials. It is hoped that as the uses of HBOT expand, with increased evidence base, "more patients will benefit from improved techniques and protocols, broadening the scope with which HBOT is used."15