Why I have a problem with HBOT

Here's the pilot study that folks who say there's research into HBOT on autism are touting. Of course, it isn't proving the efficacy of HBOT in autism.

"The effects of hyperbaric oxygen therapy on oxidative stress, inflammation, and symptoms in children with autism: an open-label pilot study."

Authors: Daniel A Rossignol, Lanier W Rossignol, S Jill James, Stepan Melnyk, and Elizabeth Mumper

There are several problems with this study.

First problem: no control group. We don't know if children without autism are less likely to have oxidative stress; we don't really know that children with autism in general have it because the studies that have found it have been small studies with similar problems to this one.

Second problem: sample size. Too small to be statistisically significant, nor was there any attempt to have a representative sample. Therefore, you can't extrapolate out past these 18 kids.

Third problem: The parental evaluation of clinical outcomes. As the authors themselves note: "The use of parent-rated scales and the fact that parents were not blinded to the type of therapy given to their child might have introduced some bias. Furthermore, there was no placebo or control group. Therefore, the improvements found in this open-label study could be due merely to chance or to the natural development of the children. In addition, it is possible that any clinical improvements observed could have occurred as a result of the increased close interaction between the child and parent/caregiver, or motivation and/or enthusiasm that may have developed in the parent/caregiver during the course of the treatments. Because this was a pilot study, the sample sizes were small which makes it difficult to make adequate and meaningful comparisons between the 2 different pressures and oxygen concentrations used. Due to these issues, a larger double-blind, prospective study that includes a control group and more objective outcome measures is warranted."

On many levels, it would be wrong if this study was used as anything other than a preliminary study which basically says this: well, gee, the parents were going to do it anyway so let's see if it changes oxidative stress levels (the argument behind the HBOT therapy).

Huh, it didn't change the oxidative stress levels (one of the arguments people are making as to whyt HBOT would help with autism) but there was a change in the parents' perception that their children got better. Never mind they are psycholigcally invested in seeing improvement. 40 sessions at 30 minutes to 2 hours. 100 to 300 dollars a session. A keen desire to see the child improve and checklists filled out by parents rather than third party blind obersvers rating. Lots of holes in this study. And yet it will be touted as proof that it helps the children.

"Eighteen children with autism, ages 3–16 years, underwent 40 hyperbaric sessions of 45 minutes duration each at either 1.5 atmospheres (atm) and 100% oxygen, or at 1.3 atm and 24% oxygen."

That's what these scientists studied. Do parents understand the huge problems with this study, with the design, sample, sample size, measurement methods? Apparently those who want HBOT listen to the folks selling it, don't actually read studies, or don't understand what the results actually say.

One person wrote how she couldn't understand why anyone would have a problem with this. Not all HBOTs are big rooms. How many kids getting HBOT are in the single person chambers barely big enough to roll over in? So, you sedating these kids? Because if your autistic child can go in a chamber that size without freaking the hell out, then you should count yourself lucky.

My other personal problem with this is is the cost, the time, the charlatans trying to sell parents home HBOTS for 10 to 20 grand. Great, so parents can administer this "therapy" at home unsupervised.

Side effects folks for a therapy that has shown no efficacy (after all if it's oxidative stress, those numbers should have improved after the treatments and they didn't):


"What are the risks or possible side effects of HBOT?
Under proper supervision, the risks of HBOT are very minimal. The most common side effect is ear pain, and patients are monitored closely for this. Rarely, oxygen toxicity, pulmonary barotrauma and vision change can be experienced.

The following list of potential side effects is reviewed with each patient prior to beginning therapy.

Otic Barotrauma (pain in the ears or sinuses). Some patients may experience pain in their ears or sinuses. If they are not able to equalize their ears or sinuses, the pressurization will be slowed or halted and suitable remedies will be applied.

Serous Otitis. Fluid in the ears sometimes accumulates as a result of breathing high concentrations of oxygen. It may occasionally feel like having a “pillow over the ear.” This disappears after hyperbaric treatment ceases and often can be eased with decongestants.

Oxygen Toxicity. The risk of oxygen toxicity is minimized by never exposing patients to greater pressure or longer times than are known to be safe for the body and its organs. The risk is less than one in 10,000 treatments.

Visual Changes (blurring, worsening of near-sightedness [myopia], temporary improvement in far-sightedness [presbyopia]). After 20 or more treatments, especially for those over 40 years old, some patients may experience a change in vision. This is usually temporary and in the majority of patients, vision returns to its pre-treatment level about six weeks after the cessation of therapy. It is not advisable to get a new prescription for glasses or contacts until at least eight weeks after ending hyperbaric oxygen therapy.

Maturing or Ripening Cataracts. Individuals with cataracts have occasionally had a maturing or ripening of cataracts.

Cerebral Air Embolism and Pneumothorax. Whenever there is a rapid change in ambient pressure, there is the possibility of rupture of the lungs with escape of air into the arteries or into the chest cavity outside the lungs. This can only occur if the normal passage of air out of the lungs is blocked during decompression. Only slow decompressions are used in HBOT to obviate this possibility. It is important for patients to breathenormally during during treatment and not hold their breath.

Fatigue. Some people may subjectively feel fatigue following hyperbaric treatment, but this is not a consistent finding.

Risk of Fire. With the use of oxygen in any form there is always an increased risk of fire."

But, some will say, my child improved. Again, objective third party measurement of improvement in behaviors? Or you saying, gosh, my child sure is quieter and calmer coming out of there. Huh. What kind of chamber did you put him in? Did you sedate him? Give him decongestants? Incentivize good behavior while in the chamber so that the child gets a treat?

Short of a third party objective measurement, you can't honestly say your own psychological need for your child to improve isn't coloring your interpretation of your child's behavior. And that doesn't mean the child's teacher or therapist saying your child's always quiet the day after, either.

Listen, I get it. I really do, from personal experience. I did the GFCF diet for FOUR years. I took any and all improvement to mean that the diet was working. Now, if it were the diet, when all three children were taken off of it, there should have been regression, additional behaviors. Gosh, no, they're doing just fine. No regression. Continued improvement. Of course, you know what also continued? The same hours of work with the children to help them master new tasks. Huh. So which is more likely to cause improvement? One-on-one work with a child on specific skill sets or HBOT, chelation, or whatever woo you want to use?

Woo, for those who don't know, is any treatment, therapy, belief, in something that has no scientific evidence to back it up. None. Like crystals for healing. Acupuncture. Homeopathy.
Some woo is harmless. Some is not.

HBOT is not harmless to the autistic child or to the parents who shell out the fortune and the time that could have been more effectively used. And there is no evidence that it fixes the problem that folks promoting it say is behind the autism.

Don't believe me? Trade four of those sessions for one-on-one sessions with the child where someone who wants to do it engages in play therapy, cognitive behavioral therapy, or social skills and then compare the child's state of well-being to after the HBOT.


kathleen said...

Well done Kim..As I have said so many times -people believe what they want to believe. When you are part of a "cure" group..you don't want to question what other parents swear by..because they want to believe so badly..it is scary, and someone is making a whole lot of money off of this.

KWombles said...

Thanks, Kathleen.

Bucket loads of money. You'd think they'd catch on.

davidbrown said...

I think the most fundamental problem of HBOT therapy is that the "treatment" involves placing the autistic child
in an artificial environment, where factors likely to cause or escalate negative behavior- noise, crowds, allergens, etc- are absent. It would not be surprising if there were genuine improvements, but one would be hard-pressed to prove higher oxygen was responsible. I think a good comparison test would be HBOT vs. a sound-proof room.
Also, I'm convinced that no one but a "pro" can be trusted to run a hyperbaric chamber safely. One grisly footnote in the history of the technology is that Nazi scientists were prosecuted for using it for intentional homicide. A layman trying to maintain and operate such a chamber could produce equally deadly results. Thus, it is completely unconscionable that some "therapists" are trying to sell families their own chambers.
-David N. Brown