This commentary is by David Bird, a resident of Barre.
I should start by acknowledging that I am not a medical professional and have undergone no formal medical training/education.
On May 25, VTDigger published a letter to the editor under the headline “Hyperbaric oxygen therapy can help with long Covid.” In the letter, the author asserts that hyperbaric oxygen therapy is a therapeutic modality that can be used to treat long Covid and implies that it can also treat autism, multiple sclerosis, Bell’s palsy, stroke, rheumatoid arthritis, and Lyme disease, among others.
At first glance, this may appear to be a fantastic breakthrough that promises to revolutionize the way we treat a variety of serious medical conditions, but I’ve heard it said that “cure-alls cure nothing,” so I think it prudent to take a closer look at a few of the author’s claims.
According to the Mayo Clinic, hyperbaric oxygen therapy involves breathing pure oxygen in a pressurized environment. Hyperbaric oxygen therapy is a well-established treatment for decompression sickness, a potential risk of scuba diving. Other conditions treated with hyperbaric oxygen therapy include serious infections, bubbles of air in blood vessels, and wounds that may not heal because of diabetes or radiation injury.
However, having established HBOT as a legitimate medical therapy for certain conditions does not exempt it from the prerequisite of being proven effective in the treatment of other conditions before it can responsibly be recommended for their treatment.
In lieu of evidence, the author puts forward the idea that HBOT “isn’t well known in the U.S., but is widely used worldwide….” Unfortunately, this argument falls prey to the logical fallacy of argumentum ad populum (Latin for “appeal to the people”), which conflates truth with popularity. It is important that we judge the veracity of assertions not by their popularity, but by the power of their evidence, so we should dig into the evidence for a few of these claims.
Autism spectrum disorder: Over the years, autism spectrum disorder has been targeted by a huge number of pseudoscientific claims, treatments and “cures.” In fact, in 2017, the FDA specifically called out HBOT in its article “Be Aware of Potentially Dangerous Products and Therapies that Claim to Treat Autism.” In much the same way Andrew Wakefield’s discredited claims about the supposed vaccine/autism link endangers communities, I worry that scientifically unsubstantiated interventions put both patients and their families at risk.
Multiple sclerosis: There are a number of nonprofits/charities that are heavily involved in the funding of research into the treatment of this life-changing illness. The MS Society, one such charity, writes “Some people with MS report benefits from using this type of treatment. But there’s no scientific evidence that HBO therapy for multiple sclerosis works well.”2 Another charity, The Multiple Sclerosis Trust, writes on their website “Whilst anecdotal reports suggest the treatment can be helpful for some people with MS, particularly with fatigue and bladder symptoms, research into hyperbaric oxygen therapy in multiple sclerosis has not found scientific evidence that it is effective.”3
Long Covid: While this area of study is necessarily in its early stages, the FDA states that “HBOT is being studied for other conditions, including COVID-19. However, at this time, the FDA has not cleared or authorized the use of any HBOT device to treat COVID-19.”4
While not addressed in this letter, I think it is also pertinent to touch on the differences between “Hard” and “Mild” HBOT.
Hard HBOT utilizes a hard-sided pressurization chamber that can achieve 100% oxygen levels and 1.5-5 atmospheres of pressure and has been cleared and authorized by the FDA for the treatment of 14 medical conditions.
Conversely, mild HBOT utilizes a soft-sided fabric pressurization chamber filled with normal air (~21% oxygen) and no more than 1.3 atmospheres of pressure. At present, the FDA has cleared mild HBOT chambers only for the treatment of acute altitude sickness and has not cleared the use of supplemental oxygen in conjunction with mild HBOT chambers, stating, “The FDA has not cleared these bags for use with oxygen tanks or oxygen concentrators. However, the FDA is aware of instances in which people used these bags to create homemade HBOT devices, which can pose the risk of fire and suffocation.” In fact, the FDA, the American Medical Association and the Undersea and Hyperbaric Medical Society have all issued statements recommending against the use of mild HBOT for treatment of any condition except altitude sickness.
I’m sure that the author of this letter and everyone at Hyperbaric Vermont is genuinely interested in helping people and convinced that HBOT is a legitimate treatment for the specific conditions they mentioned, but I worry that already vulnerable patients might be swayed by this letter to pursue a therapy that Hyperbaric Vermont itself admits on its website is “rarely covered by insurance in the US” instead of science-based medicine.
As more testing is done and rigorous randomized controlled trials are completed, it may well turn out to be that HBOT is an effective treatment for many more conditions than it is currently used for, but the fact of the matter is that there is just not evidence available currently to support these claims.
