Hyperbaric Oxygen Therapy

by Brian Dunning
November 19, 2019

Most of the time, when we see quack medical devices sold to the public, they're some sort of electronic gizmo with LED lights or something intended to impress the gullible. Generally they have no therapeutic value whatsoever — beyond any placebo effect, that is. However, some practitioners have figured out that actual medical devices, such as large and imposing hyperbaric chambers, can also be used to give the appearance of medical treatment, extracting money from hopeful patients with an impressive show of tech. Today we're going to look at the unscientific use of Hyperbaric Oxygen Therapy, an actual medical procedure that is increasingly being used for fake medical procedures.

Hyperbaric Oxygen Therapy (HBOT) involves placing the patient in a chamber with a high oxygen content at up to three times atmospheric pressure. How high that pressure is and how long they stay inside is determined by the condition being treated; it's usually between 30 minutes and two hours. Often this chamber is a tube just big enough for one person to lie in, but it can also be a room large enough to accommodate a number of people. They're basically similar to the decompression chambers used by deep sea divers, though many of those can go up to much higher pressures, and people may have to stay inside those for days or weeks.

HBOT is currently approved by the US Food and Drug Administration to treat thirteen conditions. The most obvious is decompression sickness, but also arterial gas embolisms, where you get bubbles of air in your bloodstream that can obstruct circulation. It's also used for carbon monoxide poisoning, in order to force oxygen into the blood to keeps its levels high enough while the carbon monoxide takes its time working its way out of the system. The other main type of condition HBOT is used for is chronic, non-healing wounds. The tissue in skin grafts or flaps, gangrenous tissue, abscesses, thermal and radiation burns, some crush injuries, and diabetes-related ulcers may be low in oxygen and at risk of tissue death. Exposing such tissue directly to high-pressure oxygen gets that oxygen into the cells and speeds up the healing. We also use HBOT for some anemic patients whose hemoglobin has dropped low enough that their blood can't otherwise carry enough oxygen. Beyond these conditions and one or two others, there isn't really anything that HBOT has been proven to treat effectively.

But of course, as any experience Skeptoid listener can guess, that doesn't stop the charlatans — or even just the desperate and the hopeful — from offering HBOT as a miracle cure for anything you can imagine. One of these has been autism.

In 2009, researchers representing the International Hyperbarics Association published a small study in the online journal BMC Pediatrics claiming "significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness" in autistic children given 40 sessions of HBOT at only slightly increased oxygen level and pressure. The authors' claimed mechanism was reduced inflammation in the brain and gastrointestinal tract. Although this study remains highly cited today as evidence for effectiveness, it was quickly and roundly criticized by the medical establishment for its methodological flaws and its failure to be replicated anywhere. A major red flag was its focus on brain and gastrointestinal tract inflammation, neither of which have been shown to be associated with autism.

One doctor's website offering HBOT for the treatment of acute migraine claims that it works by constricting the blood vessels that cause a migraine's pulsing sensation. One Cochrane review was able to track down only thirteen studies of this, and found only:

...Some low quality evidence to suggest that HBOT relieves pain with acute migraine headaches and possibly cluster headaches... We found no evidence that [it] can prevent future attacks.

One of the most alarming trends in the unscientific use of HBOT is its application to infants who were brain injured at birth. Lots of unfortunate conditions can cause oxygen deprivation to an infant during a traumatic birth. Brain cells begin dying within just a very few minutes, and whatever regions of the brain don't get enough oxygen die. This type of brain damage is permanent; a neuron that's dead is dead and cannot be revived. Nevertheless, some places offer HBOT as a way to re-oxygenate these dead neurons and bring them back to life — a thoroughly illogical and unscientific claim. It's like trying to force-feed a dog that already starved to death.

Much of this misinformation comes from ambulance-chasing law firms that market to the parents of brain injured babies. Many of them advocate a number of unproven or implausible therapies, as these are additional expenses that lawsuits can try to recover money to pay for. Some of these claim that HBOT reduces pressure in the brain (it doesn't), helps brain tissue to heal (it doesn't), or they make bizarre unfounded claims like this:

If your child has a brain injury or cerebral palsy, there may have been large sections of tissue either in the body or in the brain that have become dormant, and increasing oxygen in the body overall brings life back into those areas.

Worse, the use of HBOT for brain injured babies is getting promotion from the academic press, but almost entirely limited to within China and Russia, two countries with long-standing reputations for having their legitimate scientific work peppered with terrible research done to support speculative business interests. Back in 2006, the British Medical Journal published a review of the Chinese literature on HBOT for neonatal brain injuries, and their abstract concluded (in part):

Because of the poor quality of reporting in all trials and the possibility of publication bias, an adequately powered, high quality randomised controlled trial is needed to investigate these findings.

Similarly, a 2004 review by the Undersea and Hyperbaric Medical Society surveyed Russian medical literature, and found that HBOT is approved for more than 60 different conditions, including fetal asphyxia — that's just a few more than the thirteen the FDA has approved it for. Their abstract found (in part) and not encouragingly:

Most of the studies are small controlled series with an evaluation of general clinical parameters. Transcutaneous oxygen monitoring was not used in any of these studies. Double blind controlled studies were not found. Studies comparing cost effectiveness of HBOT with traditional treatment modalities were also not found.

To counter the growing wave of potentially harmful misinformation, the FDA put up a web page called "Hyperbaric Oxygen Therapy: Don't Be Misled." It says:

No, hyperbaric oxygen therapy (HBOT) has not been clinically proven to cure or be effective in the treatment of cancer, autism, or diabetes. But do a quick search on the Internet, and you'll see all kinds of claims for these and other diseases for which the device has not been cleared or approved by FDA.

They then give the following list of some of the many things for which some practitioners are selling HBOT, but which lack any evidence that it works: AIDS, Alzheimer's disease, asthma, Bell's palsy, brain injury, cerebral palsy, depression, PTSD, heart disease, hepatitis, migraine, multiple sclerosis, Parkinson's disease, spinal cord injury, sports injury, and stroke. In addition, the Mayo Clinic has a web page that lists all of these plus adds a few more: allergies, arthritis, autism, cancer, chronic fatigue syndrome, cirrhosis, fibromyalgia, gastrointestinal ulcers, and heatstroke. Yet, search the web for any of those conditions plus the term HBOT, and you'll see that someone somewhere is aggressively promoting it as a miracle cure.

I wish I could say that at least HBOT isn't going to hurt anyone, but the fact is it can. Even proper use of it carries risk. Serious injuries can result. These can range from sinus pain, ear pressure, and joint pain all the way up to paralysis and air embolisms. Most frightening of all is the risk of fire in a high-oxygen environment. In 2009, a doctor in Florida was treating a 4-year old boy for cerebral palsy in a hyperbaric chamber (reminder: it doesn't work for cerebral palsy). The chamber burst into flames, killing both the boy and his grandmother, who had brought him to the United States for the treatment from Italy because the fire danger makes such chambers illegal there. It was found that the fire was ignited when the grandmother adjusted a cushion, causing a spark from static electricity. The National Fire Protection Association warns of all the potential sources of static electricity including your cell phone and other devices and the type of fabric in your clothing. A study published way back in 1997 found 77 such deaths in 35 clinical hyperbaric chambers. And there are now more than 1,300 chambers in the United States alone.

Of greater concern is that publicity generated by professional athletes and other celebrities has jump-started a market in home hyperbaric devices. Called bag chambers, these can retail from between $7,000 and $17,000 and can be used by anyone in the privacy of their home, unsupervised. These devices are cleared by the FDA only for treatment of altitude sickness. Thousands have already been sold, and they now outnumber the clinical chambers. It's probably only a matter of time before we start getting reports of fire deaths and paralysis cases from these devices. In 2011 a valve in a privately purchased bag chamber was defective, killing a 19-year-old man whose family was attempting to treat his autism.

Unfortunately, the FDA has no say in the use or misuse of devices they approve. Their only role is to determine if they can safely be used as intended, and to specify what those intended uses are. So we can probably expect more such accidents, and more such sales as well. And the effect that has? An FDA rep put it succinctly:

Patients may incorrectly believe that these devices have been proven safe and effective for uses not cleared by FDA, which may cause them to delay or forgo proven medical therapies. In doing so, they may experience a lack of improvement and/or worsening of their existing condition(s).

If you have any doubts about any device, you can always look it up on the FDA website and make sure you're using it only for its intended purpose — or better yet, ask a doctor, and get a second opinion if anything looks remotely shady. Because when it comes to your health or that of your family members, you should always be skeptical.

By Brian Dunning
Follow @BrianDunning