Controlled Evaluation of the Effects of Hyperbaric Oxygen Therapy on the Behavior of 16 Children with Autism Spectrum Disorders

21 Apr

Hyperbaric oxygen treatment (HBOT) has become a big topic in the world of CAM (complementary and alternative medicine) and autism. An upcoming parent convention with a focus on CAM is even sponsored by an HBOT company. A few papers have come out, without much clear evidence of benefit.

A recent paper looks again at HBOT. This paper has a few limitations. Amongst these: there were only 16 participants and, well, I consider papers by Thoughtful House and by Andrew Wakefield in particular to be somewhat problematic.

Here is the abstract:

Controlled evaluation of the effects of hyperbaric oxygen therapy on the behavior of 16 children with autism spectrum disorders.

Jepson B, Granpeesheh D, Tarbox J, Olive ML, Stott C, Braud S, Yoo JH, Wakefield A, Allen MS.

Thoughtful House Center for Children, Austin, TX, USA.

Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total of 16 participants with autism spectrum disorders. No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study. This study represents the first relatively large-scale controlled study evaluating the effects of HBOT at the level of the individual participant, on a wide array of behaviors.

One problem with HBOT studies in the past is the attempt to use a placebo like therapy. It seems to this observer at least that it would be quite easy to distinguish placebo vs. real HBOT. The current study avoids that. They took data during a baseline period, during the HBOT therapy weeks and a post-HBOT period. They found that there was no benefit.

These findings diverge considerably from those of Rossignol et al. (2009). The current study controls for the potential ‘‘washing out’’ of the effect when group data are averaged (as must be done in a between-groups design) by carefully measuring potential changes in 11 topographies of behavior over time across 16 individuals. If there was a subgroup for which HBOT was effective, it seems likely that at least one such child would have participated in the current study. The lack of an effect for any participant in the current study makes the existence of such a subgroup seem implausible.

The paper concludes:

News programs and community blogs report that many families of children with autism are using HBOT therapy. The cost of such treatment may range up to $150 per hour. Families report using anywhere from 40 to 120 h of HBOT. These hours are in lieu of other therapies such as applied behavior analysis, speech therapy, and occupational therapy and do not include travel time to the medical center where the therapy is provided. Some families purchase the chambers in order to provide therapy in their home. A number of websites focus on renting ($1,395 per month) and selling ($8,495–27,995) chambers to families. Given the financial and time-investment required for HBOT and the conflicting study outcomes to date, we cannot recommend HBOT as a treatment for autism until such time as more conclusive favorable results are demonstrated.

This is consistent with a previous study which included one of the above authors, Randomized trial of hyperbaric oxygen therapy for children with autism, which concluded:

This study found HBOT to have no significant beneficial effect on ASD symptoms. The experimental design of the current study is of a higher rigor than those employed in previous studies which have suggested that HBOT is effective. Further, the dependent measures included were far more comprehensive than those included in previous studies; therefore it is unlikely that an effect was present which was not detected. Based upon the findings of the current study, HBOT delivered at 24% oxygen at 1.3 atmospheric is not recommended for the treatment of ASD symptoms.

Do’C over at the AutismStreet blog has followed the HBOT research pretty closely. Here is his list of articles skeptical about HBOT.

My own view:
HBOT is expensive, time consuming, not effective for treating autism and will continue to be promoted heavily to parents looking for a way to help their children. There is something profoundly wrong with the world of CAM and autism if they don’t move away from therapies like HBOT.

76 Responses to “Controlled Evaluation of the Effects of Hyperbaric Oxygen Therapy on the Behavior of 16 Children with Autism Spectrum Disorders”

  1. Neuroskeptic April 21, 2011 at 09:38 #

    Hah! Hyperbaric Oxygen Therapy. “So crazy, even Wakefield thinks it’s crazy.”

  2. Greg K April 21, 2011 at 13:59 #

    What? Thoughtless House shooting down one of their own alternative “treatments”? Why? To prove they’re “mainstream”? What? The world doesn’t make sense anymore.

  3. Audrey April 21, 2011 at 14:20 #

    Not only is it ineffective, HBOT has nontrivial risks. Certainly there are medical disorders for which the benefits outweigh the risks (like carbon monoxide poisoning), but it is irresponsible to expose a child to the risks of HBOT for a non-indicated condition. Risks include eardrum rupture, seizures, cataracts, barotrauma to organs, and – especially when you use a home system – the whole damn system catching on fire. O2 is highly flammable, just ask the Apollo 1 crew.

  4. Julian Frost April 21, 2011 at 14:22 #

    Audrey, we know the fire risks. One of the posts on LBRB mentioned a fire starting in a chamber with an autistic child and a caregiver in it. The caregiver died in hospital. The child (luckily) survived.

  5. Rose April 21, 2011 at 15:21 #

    Nature abhors a vacuum. Until science comes up with something…

  6. Chris April 21, 2011 at 16:18 #

    Julian, both the child and his grandmother died:

  7. Sniffer April 21, 2011 at 20:06 #

    Dear All,

    It`s dangerous Oxygen kills you,just ask any all having a joke?



  8. Chris April 21, 2011 at 21:21 #

    It is not a joke. The child and the grandmother died in a fire created in the HBOT chamber. Please, also, go up and re-read Audrey’s comment.

  9. Sniffer April 21, 2011 at 22:04 #

    Dear Chris,

    Your obtuse.



  10. Ron Mills April 21, 2011 at 22:47 #

    We find scant evidence and not much biologic rationale to support hyperbaric oxygen for autism. Your post seems to me a fair assessment of this study using mild HBOT (1.3 atm) and room air (24% oxygen). It mimics and handily refutes Rossignol [BMC Pediatr. 2009 Mar 13;9:21]. Both DAN and CARD centers bring troubling bias to their investigations. To settle matters, interesting future studies might deliver 100% oxygen at higher pressures (2.0 atm or higher) in fully accredited, independent, and professionally staffed centers. See our autism page and blogposts for more information. Cheers. R

    Ron Mills

    • Sullivan April 21, 2011 at 23:13 #

      To settle matters, interesting future studies might deliver 100% oxygen at higher pressures (2.0 atm or higher) in fully accredited, independent, and professionally staffed centers.

      The real DAN (Divers Alert Network) has a good page on oxygen toxicity. Navy dive tables cut off at 1.6 atmosphere O2.

      From that page:

      Above 1.6 ata is the “red light” area. Just don’t do it. Yes, there is evidence that short exposures at higher levels of pO2 (oxygen partial pressure) are possible but so are convulsions. At these levels, oxygen exposure depth/time limits must be adhered to. Even mild exercise may put divers breathing high-density nitrox mixes at increased risk; and even open-circuit scuba divers can achieve durations likely to get them into trouble at these levels. Diving using these high partial pressures of oxygen should be left to the trained professionals who can weigh the risks and benefits and who have the necessary training and support structure in place, if an oxygen convulsion occurs.

      This leaves me at a loss–why should disabled people, with a condition some have said involves oxydative stress, be subjected to higher partial pressures of oxygen than Navy divers? Especially considering no real mechanism has ever been put forward for why HBOT would work in the first place.

      Sorry if I find your suggestion irresponsible.

  11. Chris April 21, 2011 at 23:19 #

    Sniffer, do you think Ron Mills is joking?

    People are like him are advocating dangerous treatments, so it is no joke.

  12. Rosa April 21, 2011 at 23:32 #

    Audrey, oxygen is NOT flammable.

  13. Rose April 21, 2011 at 23:34 #

    People searching serves one purpose. It brings our children to the attention of true science, which is a deep curiosty. Suddenly, children who have been written off are seen as interesting.

    I know no one forgets that at one time, medicines answer was to institutionalize children, and parents were to forget about them. The wheels of progress move slowly. We are barely past that. We drug them, and send them to school. Now, based on the attention parents are getting for looking outside the loop, our children are a new diversion. Had it not been for parents serving as a buttress between the “brilliant minds of science” and their children, we’d still be counselled to forget about them.

    Kev, why did you once believe? Were you looking for answers that science couldn’t give you? Have they given you any to this day?

    I’d be lying if I said I didn’t go to Pub Med to check out the new ideas. A part of me still looks for a miracle of science to make life easier for my son, or maybe selfishly just for me. But I do it far, far, far less than I used to.

    People die from from “questionable” treatments. People die from standardized ones, too. I’ve said my piece. Guess I’ll let you get back to your regularly scheduled program.

  14. Sullivan April 21, 2011 at 23:49 #


    “Audrey, oxygen is NOT flammable.”

    Yes and no. Oxygen is not what we typically think of as “flammable” but it is 1/2 of the reaction when something burns, right?

    Many things are flammable in pure oxygen which are not flammable normally. That was the lesson of Apollo 1.

    One problem with home HBOT is that people use oxygen concentrators to enrich the O2 content beyond the levels the chambers are spec’d for.

  15. Sniffer April 21, 2011 at 23:55 #

    Dear Sullivan ,

    Yet again ,you pretend to be a pusher for helping autism.In reality all we see is cold water being thrown over nearly every article printed.

    Below after a fast search some information I found from a web site.

    Local MS centres in the UK

    Dr Dan Rossigial showed that HBOT helps autistic children in the
    Following areas:

    Relative Cerebral Hypoperfusion
    Neuroinflammation and GI Inflammation
    Immune Dysfunction
    Oxidative Stress
    Relative Mitochondrial Dysfunction
    Serotonin Abnormalities

    Heres another
    Pilot Study of HBOT Effect on Autism Symptoms Published

    Heres another

    Heres another This is the International Hyperbaric Association

    Heres another This is a study by Lewis Mehl-Madrona, M.D., Ph.D.

    .Last I shall leave you with a video from a parent on You Tube a before and after video



    • Sullivan April 22, 2011 at 00:23 #

      The conclusions are not mine, they are those of the authors:

      Bryan Jepson • Doreen Granpeesheh • Jonathan Tarbox • Melissa L. Olive • Carol Stott • Scott Braud • J. Helen Yoo • Andrew Wakefield • Michael S. Allen

      They, not I, stated:

      Given the financial and time-investment required for HBOT and the conflicting study outcomes to date, we cannot recommend HBOT as a treatment for autism until such time as more conclusive favorable results are demonstrated.

      Those authors addressed the Rossignol study:

      They [Rossignol et al]reported no significant worsening of oxidative stress, a nonsignificant trend of improvement in C-reactive protein values (in a small subgroup that started out high) and improvement in parent reports of some measures associated with autism (speech, motivation and cognitive awareness). However, the weaknesses of the open-label design and the lack of a control group make it difficult to reach definitive conclusions. Specifically, it is possible that the improvement in parent report measures was due to a placebo effect, or due to improvement over time due to other concurrent treatments taking place outside of the HBOT.

  16. Ron Mills April 22, 2011 at 00:50 #

    Thanks for the reply, Sullivan. You and I read the Divers Alert Network page quite differently. I’ve written briefly of the sometimes baffling physics and history of HBOT dosage (pressure, oxygen, and time) at and elsewhere. Divers experience 2.36 atmospheres absolute (ATA) under 45 feet of seawater (FSW), and that’s the HBOT pressure most common in the medical literature and in common therapeutic use today. Patients in hyperbaric chambers get periodic breaks from pure oxygen to prevent toxicity. Others have conjured up some (some) rationale for HBOT in autism. Perhaps treatment should be strictly limited to well-controlled clinical trials. Yet we see an awful lot off-label HBOT for autism in the US today, and so we’d like to see the hypothesis clearly proven or disproven. HBOT is serious medicine with serious potential side-effects and safety concerns. You and I agree that anyone using HBOT for autism in clinical practice today is working outside the realm of evidence-based medicine.

    • Sullivan April 22, 2011 at 00:55 #

      “Divers experience 2.36 atmospheres absolute (ATA) under 45 feet of seawater (FSW), and that’s the HBOT pressure most common in the medical literature and in common therapeutic use today”

      To be clear–divers experience 2.36 ATA of air, not oxygen. At 20% O2 for air, that amounts to 0.47 ATA O2. One would still experience a higher O2 partial pressure with an oxygen mask.

  17. Chris April 22, 2011 at 00:56 #

    Scuba divers do not fill their tanks with a 100% oxygen.

  18. Ron Mills April 22, 2011 at 01:21 #

    Yes about the partial pressure. In medicine, unlike diving, oxygen is a drug. Therapeutic HBOT dosages (pressure + oxygen + time) lie somewhere between harmlessly ineffective and dangerously toxic. It’s a regimen practiced safely and effectively in >1000 US centers every day. Our question has been, Does HBOT help children with autism? We find scant evidence. We await further study. Period.

    • Sullivan April 22, 2011 at 01:26 #

      Ron Mills,

      for mild HBOT, you have evidence. It doesn’t work for autism. I hope you will include that in your links.

      For high pressure oxygen, one must have a reason for testing it, since it is a drug. “We want to know” isn’t good enough. Autistics are prone to epilepsy and seizures, for one thing. Any thoughts on the seizure threshold in autistics for high pressure oxygen, or will we just find this out while we go on a high pressure fishing expedition?

  19. Ron Mills April 22, 2011 at 02:04 #

    Neither CARD nor Rossignol meet my criteria for conclusive evidence. Popular off-label usage will continue as long as the jury’s still out. But, yes, more commentary forthcoming on null findings with mHBOT on our Autism page. (One might expect null mHBOT findings for any indication.) We don’t encourage further study in autism, but we know it’s coming, and we’d rather see more thoughtfully designed and well-controlled trials than more wild-ass guessing. You’re right to be concerned about seizures. Investigating docs, nurses, and techs can and do handle such high-risk patients in large multiplace chambers all the time. And I take your “fishing expedition” comment most seriously. Let’s nail down a mechanistic theory of HBOT’s efficacy in autism, or let’s scotch the whole idea.

  20. Sniffer April 22, 2011 at 10:58 #

    Dear All,

    These are my observations having helped a friend attend HBOT dives over a few years.

    Just because a protocol never gave up any results it does not prove that is the result for all.

    Each patient is different and to herd a group of children and give them all the same protocol to the ends of a test is wrong to start with.

    If you were going to treat anyone meaningfully with oxygen and HBOT a few factors are worth looking at, prior to treating with HBOT.

    1. Possibly the temperature in the chamber would make a difference to the patients blood circulation. If the blood cannot circulate due to cold or bad circulation how is the treatment going to work.

    2.Depth of a dive to suit the individual patient .If you were being stringent, surely you would take a blood sample before the dive to see the content of oxygen etc and after the dive to see any change. From this you could either keep the dive at the same depth if showing no change or deepen or lessen the depth until you see beneficial improvement in the blood.

    3. Oxidative Stress ,simple enough to test for if your doing the HBOT dive to any worthwhile standard.

    This test utilizes a blood sample in order to evaluate the body’s oxidative stress status and antioxidant reserve. This test can help practitioners identify underlying causes and perpetuating factors for many clinical disorders and to customize specific treatment programs.

    Again one apple bad does not prove that all the apples are bad .

    Treatment in the UK is free from any MS center link provided above.

    HBOT in the Uk is free through your NHS .Getting it approved at Dundee is another matter.

    Hundreds of videos on You Tube showing parents with children and Autism improved.

    No scientific evidence ,well are you at all surprised if Pharma cant patent Oxygen?



  21. Sniffer April 22, 2011 at 11:04 #

    Dear Sullivan ,

    And anything that results in a sudden lack of oxygen or a reduction in blood flow to the brain can cause a seizureas you well know.

    Whats the problem with Oxygen and HBOT,I fail to see your logic ?



  22. Ed Betts April 22, 2011 at 17:39 #

    The discussion of free-swimming divers and oxygen seizures has no relationship to patients undergoing HBOT. Do NOT let the Divers Aletrt Network(DAN)information be considered relevant to HBOT. It relates to oxygen exposures for divers. Carbon dioxide is the prime catylist for an oxygen seizure and should this occur while underwater using a standard open-circuit mouthpiece death by drowning is the enevitable result…. Hence the conservative approach regarding dosages for divers.

    HBOT in a chamber finds the patient resting, supine, non-speaking and with a low respirationj rate. Duration Tolerances are at the very least, doubled. Seizure threshholds are greatly increased.

    It was I who educated the diving industry and yes, even DAN regarding the true limits of oxygen exposures. A very complex topic but not an issue with relation to HBOT & Treating for Autism.

    Ed Betts

  23. Sniffer April 22, 2011 at 20:08 #

    Dear Ed Betts,

    Agreed with most of your post .

    “HBOT in a chamber finds the patient resting, supine, non-speaking and with a low respirationj rate. Duration Tolerances are at the very least, doubled. Seizure threshholds are greatly increased.”

    In the chambers I have seen they play scrabble, talk as if at the dentist, and they have games of cards etc. Breathing is far from shallow. In general and under a controlled protocol where you are limiting the patients you could be right .In my limited exposure to HBOT,I have never read of anyone having a seizure in a chamber unless they had a heart condition etc to start with.



  24. Prometheus April 22, 2011 at 20:40 #

    Ed Betts claims:

    “Carbon dioxide is the prime catylist [sic] for an oxygen seizure and should this occur while underwater using a standard open-circuit mouthpiece death by drowning is the enevitable [sic] result…”

    I’m going to give Mr. Betts the benefit of he doubt and assume that when he refers to carbon dioxide as “the prime catylist [sic] for an oxygen seizure” that he means low blood carbon dioxide. While it is true that seizures are also seen with high blood carbon dioxide, these are usually due to either hypoxaemia and/or low blood pH rather than the “catylitic” effect of carbon dioxide.

    Even so, he’s still wrong. Oxygen-toxicity seizures can (and do) happen at normal blood carbon dioxide levels. While hyperventilation (leading to low blood carbon dioxide) can lower the threshold for seizure (it is a common technique used during EEG tests for seizures), it is not required for oxygen-toxicity seizures.

    There is a fairly large body of data showing that many autistic children already have a reduced seizure threshold (even without hyperventilation) and – as a result – would be expected to experience seizures at lower oxygen partial pressures than the “average” person of their age.

    Two factors need to be considered when looking at the safety of HBOT in autistic children: potentially lowered seizure threshold and the normal distribution (“bell-shaped curve”).

    As I mentioned above, there are autistic children with lowered seizure thresholds – we just can’t tell who they are until they have a seizure. In addition, the sensitivity to CNS oxygen toxicity follows a normal distribution. As a result, there are some people who – even without autism – will have seizures at a lower oxygen partial pressure than the “average” person. The Navy and DAN dive tables take this into account, but only to two standard deviations or so.

    The result is that the only reason mild/minimal hyperbaric oxygen therapy (mHBOT) hasn’t caused a number of seizures to far is that [a] there haven’t been that many children who have actually received 100% oxygen at 1.3 atm and [b] the “treatment” is at the lower edge of oxygen toxicity – in terms of oxygen partial pressure and duration – so only a small fraction of a percent of children will seize during a typical “treatment”.

    The argument – such as it was – for mHBOT in autism was that it might help and was so mild that it probably couldn’t hurt. Now that studies (even by people with a monetary incentive to see it work) have shown that mHBOT doesn’t work, there are already some people agitating to “turn it up”. If 100% at 1.3 atm doesn’t “work” for autism (and it doesn’t), they argue that this means we need to go to higher pressures. And it won’t take much more pressure before the children are in the range of real danger.

    And what are the data showing that HBOT (mild, minimal or even the “full Monty”) “works” for autism? Sadly, there are none. All that exists is a “hypothesis” that HBOT will reverse the neuroinflammation and poor brain perfusion that also haven’t been convincingly shown to exist in autism.

    Maybe it’s time to acknowledge that HBOT lacks any evidence of efficacy in autism and that “turning it up to 11” is only going to put children at risk. Perhaps more studies of children might show that higher oxygen partial pressures “work”, but there is also a known risk of seizure (not to mention fire). This is not something that should be done by minimally trained people in a clinic setting.


  25. Sniffer April 22, 2011 at 21:01 #

    Dear Prometheus,

    Most of your points are turned against you on the link below.

    As you know the temporal region of the brain, an area that is believed to be inadequately oxygenated in autistic children.

    Yours Sincerely


  26. Laura H Betts April 22, 2011 at 21:51 #


    There are a few points overlooked in relation to this discussion:

    In regards to the flammability of oxygen and the fact that they are “using concentrators”; by engineering design, the vent rates of most”portable chambers” do not allow the F02 to climb above 25%. When ambient FO2 rates are monitored (which I feel is prudent) I’ve rarely seen it climb above 23.5%… So person’s that just assume they are getting the same “dosage of oxygen”are misinformed. Dosage is a relationship of the fraction of oxygen in the breathing mixture, ambient pressure and the type and efficiency of the Built in Breathing System.

    In regards to Oxygen Toxicity: Oxtox is one of the MOST misunderstood concepts across elevated partial pressure pathophysiology. As there are some divers on this thread do you remember it used to be called “sneaky pete”? No one really knew when or where he was gonna get ya… It’s not a mystery and it hasn’t been for over 20 years. Oxygen exposures are known and the duration of the dive (whether it be in the ocean or a chamber) can be PLANNED accordingly with a safety factor. Replace the fear with knowledge and make informed treatment decisions regardless of what, where or how you you choose to treat. CNS Oxygen Toxicity leaves no forensic signature and technically does not “cause harm.” The injury in scuba divers is caused because the regulator falls out of their mouth and they drown. The injury in the case of HBOT could potentially be from the physical movements being caused by a seizure but I’d challenge any chamber operator that would stand idly by and watch someone convulse rather than just simply stop the flow of oxygen to the mask allowing the seizure to consequently dissipate withing seconds of doing so… Maximum duration limits for a single exposure HBO-Dive at an actual oxygen dosage of 1.3 ata are 360 minutes… I believe a 90 minute exposure (the average run time duration of a HBOT session) is reasonable with an acceptable safety factor. And if you want to know where I got that number come take one of my classes and I will personally show you how to do the MATH (yup it’s just math and physics) for yourself.

    In regards to the study that started this thread there is a real piece of information being overlooked. 24% FO2 at a Pressure of 1.3 ata is an oxygen dosage of about .30 ata NOT 1.3 ata. In layman’s terms if doc says take 130mg and you only took 30mg would you be surprised if you didn’t get better… I wouldn’t either. There are studies that demonstrate efficacy for the treatment of Autism one of which done by “M. Markley, Ph.D., CHT” (email me if you would like a copy I have a PDF) and there is a tremendous amount of anecdotal evidence… But since pressure and dosage are rampantly incorrectly used interchangeable by there is little way to weed through what is placebo and what is fact. I personally believe there are many that could have benefited from HBOT that discontinued (gave up) because of a deficiency in dosage and/or treatment decision based on such misinformation. This “dosage dilemma” is not just applicable to autism. I’ve seen the same scenarios across other conditions that have well established protocols.

    There are no easy answers here. I’ve seen the differences in children with autism first hand. I truly believe in HBOT but applying the same protocol to everyone for every condition with only tidbits of information doesn’t help the cause. If this thread proves nothing else, those that are seeking HBOT have a daunting task of weeding through fact and fiction.

    Laura H Betts

    • Sullivan April 23, 2011 at 00:45 #

      “CNS Oxygen Toxicity leaves no forensic signature and technically does not “cause harm.””

      Do you have data on that for people with autism and/or epilepsy?

      There are no easy answers here. I’ve seen the differences in children with autism first hand.

      I can find anecdotes all over the web. What I can’t find is data that supports the anecdotes. I can find anecdotes for many autism therapies which have good evidence that they don’t actually work. Secretin comes to mind as the most well-known example.

      What is missing is anyone saying by what mechanism HBOT would have an effect on autism.

      “There are studies that demonstrate efficacy for the treatment of Autism one of which done by “M. Markley, Ph.D., CHT” ”

      Why not provide the pubmed link?

  27. daedalus2u April 22, 2011 at 22:59 #

    I wouldn’t even call it a hypothesis, it is a wild-assed-idea. There is no rational physiology behind it.

    Sniffer, do you have any data that shows any region of the brain to be inadequately oxygenated in autism?

    Reduced blood flow is not synonymous with reduced oxygen level.

  28. Ed Betts April 23, 2011 at 00:01 #

    Dear Prometheus,
    I do not wish to start any flaming diatribes however the volume of missing information here leaves us incapable of completely discussing this complicated topic.

    Let me offer a few points,

    You stated, “Oxygen-toxicity seizures can (and do) happen at normal blood carbon dioxide levels”. Yes but at VERY high dosages and after a significant period. i.e. >2.0 ata and approaching 2 hours without airbreaks.

    I have been training physicians for about twenty years concerning oxygen issues and have conducted thousands of HBO treatments and almost 10,000 in-water dives and supervised asa guess 50,000 dives. 2 ata is not an extreme chamber dosage. Yes, for in-home care it beyond the scope of the average family and is frankly unnecessary for the topic under discussion.

    Incompletly stated oxygen toxicity is a time/pressure relationship. CNS-type toxicity is a funtion of 3 factors: PO2, tO2 and PCO2. Individual variations in susceptability are minimally significant.
    If you have sufficient PO2 (partial pressure of oxygen) (% times pressure for lay persons), sufficient time of exposure for the dosage ….tO2 (see ANDI Chart 2-4H) the onset of a seizure is either shortened or extended depending upon the PCO2. CO2 loading (workload)….. hence the free-swimming diver is cautioned to keep the dosage of 1.6 to less than 45 minutes. This dosage administered in a chamber or while the diver is at rest can be extended to durations beyond 2 hours and even longer if 5 minute air breaks are incorporated. Simple inquire at any wound-care facility and you will find that 2.2 ata is routinely administered to diabetics, gereatrics and burned children for 60-75 minutes or even longer with air breaks.

    I am unaware of any predisposition factors of low carbon dioxide.
    Rebreather divers go to great lengths to minimize the CO2 content of the breathing loop. An Ideal is even as low as 300 ppm.

    The ONLY reason I am bothering to respond here is that I am forced to do so. I do not want the mis-information concerning oxygen to be the reason for not using HBOT. I am not advocating the treatment for Autism, only that HBOT is great for edema and inflammation reduction while also giving the immune system a boost. Choose another reason for not utilizing this modality but please ……. Oxygen seizures?

    The diving industry has come into the light kicking and screaming but now has a 20 year history of enriched air nitrox diving and oxygen decompression and closed circuit rebreathers and more. There exists not a single case of a CNS seizure occuring on a single exposure recreational dive at a value of 1.6 ata or less. 20 fsw equivalent. Not one! How’s that for individual susceptabilty?

    I challenge you to find any cases of “death from oxygen seizure”. Death from drowning? yes but not in a gasous environment. Neurologists state that CNS seizures leave no forensic imprint and no known lasting negative impact.

    The chamber operators (I have trained 100’s) infrequently see a seizure occur. If so the procedure is to switch to air and let the patient recover. Although alarming to watch the issue is NOT the reason to cancel the use of HBOT. The correct procedure followed by medical staff is to continue the therapy regimen by reducing the dosage a bit and increasing the anti-oxident supplement.

    I understand the concern but ignorance prevails. There is way too much more info to support my point and 100’s of pages of published texts with my name as author.

    Suffice to say that a 1.5 ata dosage is pretty benign in a chamber and perfectly OK for an in-home administration exposure of even 3 hours.

    Sorry to sound arrogant here but my credentials are out there. If I didn’t state my experience I would be just another one of the masses speaking about a topic that requires a bit more than reading a few website postings and continuing to attempt to make a smart decision from a dumb position.

    Best wishes,

    Ed Betts

    • Sullivan April 23, 2011 at 01:15 #

      “There exists not a single case of a CNS seizure occuring on a single exposure recreational dive at a value of 1.6 ata or less.”

      People are using pressure of O2 and total pressure without being specific. That raises a lot of red flags for me.

      Recreational nitrox would be 36% O2 as the usual max, correct? So we are still talking about 0.58 atmospheres O2 as the partial pressure. This is a long way from 2 atmospheres of pure O2. Where is the data showing that a kid with an O2 mask (which should reach this partial pressure of O2 or more) shows any gains? Wouldn’t that be the first step?

      So, what do you tell the parents of a kid as to what the risks are? Since there is no idea of what the mechanism would be to treat autism, there is no real information as to what the mechanism would be for an adverse reaction.

      Are there adverse reactions from HBOT? Possibly rarely, but there are reports. For example:

      Focal status epilepticus induced by hyperbaric oxygen therapy.
      Seckin M, Gurgor N, Beckmann YY, Ulukok MD, Suzen A, Basoglu M.

      Clinic of Neurology, Atatürk Training and Research Hospital, Izmir, Turkiye.

      generalized tonic clonic (GTC) seizure activity because of central nerve system oxygen toxicity is a rare but recognized effect of HBOT (hyperbaric oxygen therapy). Almost all case reports and database analyses about the relationship between seizure activity and HBOT point out that GTC seizures and status epilepticus are more likely to occur as a result of the treatment and there are only few reports demonstrating partial seizures.

      an 87-year-old male patient was admitted to our clinic because of tonic-clonic contractions on his left arm. He was under HBOT because of a decubitis ulcer. After repeated exposures to hyperbaric oxygen, he had contractions on his left arm. He was diagnosed as focal motor status. There was no evidence of acute ischemia or mass lesion on brain magnetic resonance imaging. IV phenytoin (diphenylhydantoin) 20 mg/kg was given over 30 minutes and continued orally with phenytoin at a dose of 300 mg/d. He had no subsequent seizures.

      GTC seizures or status epilepticus as a result of GTC seizures are more common than focal seizures as neurologic complications of HBOT. Partial seizures as a neurologic complication of HBOT have rarely been reported and to our knowledge, this is the first case which is characterized by focal status epilepticus induced by HBOT.

      This isn’t a simple seizure. This was status.

      Are the risks likely low? Yes. Are they warranted–that is the question. mHBOT doesn’t work. No one has data saying that O2 levels approaching 1 atmosphere pressure are benefical–or we would all be paying a lot less than HBOT prices for O2 masks. I don’t see that there is a reason to ramp the pressure up without giving a reason.

  29. Ed Betts April 23, 2011 at 01:12 #

    Dear Sullivan,

    I do have the Markley data. I do not know the pubmed link. I will get the paper for you Monday.


    • Sullivan April 23, 2011 at 01:34 #

      I can find the Markley manuscript on the web. I can not find any paper in Pubmed with his name and autism as search terms. This leads me to the conclusion that this was never refereed. Perhaps I am wrong.

      Given the results of Markley that are oft quoted on the web, there would be almost no way for the team which wrote the paper above to have missed the effect. I think most people on this discussion agree that Thoughtfulhouse is not the most reliable source for scientific data. However, I also don’t see the results of Markley repeated in the Rossignol studies (again, not a source I go to for reliablity, but there isn’t much out there).

      I will stand by my statement that there is no good data indicating that HBOT in any form is beneficial for treating autism.

  30. Laura H Betts April 23, 2011 at 03:36 #


    I offered to send the PDF of the Markley study to anyone whom asked. I do not know why that specific article does not come up on Pubmed. (Anyone?) The data is well presented with cited references and at the least, worth reading.

    Here is a direct link to the article republished on the HyperbaricsRx site for those that choose to read it:

    Anyone whom would also like a copy of the PDF simply need ask. As far as “real” studies on HBOT and Autism there isn’t much and honestly I doubt there will be anytime soon. I personally would applaud a study that utilized varying dosages along with an attempt at a real placebo as “air under any pressure” is technically a higher dosage. (And was NOT funded by an interested party either.)

    Oxygen is technically free. It cannot be patented. There is no billion dollar pay out here to justify research funding. The business of medicine in the United States is much of the reason why HBOT is only approved for 13 indications and therefore rarely covered by insurance. The argument of HBOT being off-label is the primary reason for coverage declination while a mind boggling amount of anti-psychotics (and other behavioral modifying drugs) that have NEVER been tested nor are approved for children are prescribed every day.

    One of the main points of this thread has been the risks vs. benefits of HBOT. So I ask where is the conclusive study showing the off label application of drug A, drug B etc is beneficial? There aren’t any, yet conventional medicine accepts such acts and they are common place. There are pages upon pages of known risks and serious, life threatening side effects yet we’ll pop a pill with reverence and submission while we argue about a little oxygen. Everything has risks and somethings have more than others. Is HBOT right for you and your family? Perhaps, perhaps not… But to those of you that would condemn it for a lack of “good data” or “the risks” I would ask you to consider every therapy with a critical mind, in the same manner rather than with current blatant acquiesce.

    Laura H Betts

  31. Chris April 23, 2011 at 07:53 #

    Ms. Betts, and the reason that document has not been reviewed is because… ?

    Do tell us about the comments from the journals that are indexed at PubMed you submitted where you submitted that research.

  32. Sniffer April 23, 2011 at 20:21 #

    Dear Laura,

    Superb post .You cant write up fairer than you have .70% of patients that have chemo die within two and a half years ..and thats an Accomplishment ,what do we say Chris??



  33. Chris April 24, 2011 at 03:40 #

    Sniffer, you are presently off topic. This is not an article on cancer treatment.

  34. Laurent April 24, 2011 at 09:30 #

    Money for nothing and the cheap ways of hope.

    Waste of money to say :

    “No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study.”

    The money factor is the first elimitating factor in selecting ways to autism treatments.

    For this reason, presently, the best tracks are in old (and cheap) medications/drugs used for something else. Clearly the ways of hope are cheap ways.

    It’s the same for the education ressource. Reading T.Grandin you can understand that old (and rigid) education is highly consistent for kids with autism. But there is no money promoting old education. For money makers, ABA seems a better way.

    What I can see around is too much rich parents trying a lot of stupidities from quackers and official “knowers” .

    Stupidity and money are the first enemies of our children.

  35. Sniffer April 24, 2011 at 12:23 #

    Dear Laurent

    “demonstrating that HBOT was not an effective treatment for the participants in this study.”

    Correct one size does not cure all.It is a sad day when one has to refer to You Tube for medical proof as parents are doing in droves.The Lancet no more,pub-med no more,BMJ no more,

    Yours Sincerely


  36. Rose April 24, 2011 at 15:25 #

    I LOVE you, Laurent!!!! That’s some badass wisdom, well worth the free cost.

    Money was ALWAYS the decision-maker for us. If it wasn’t free, or damn near…forgettabout it. We did a form of ABA for free…I’ll be damned if I’m gonna send a psychiatrist’s kid to college. I used the same book they did, and taught my son languagae via pictures, as they suggested. That was what it amounted to, althoough I didn’t make him look into my eyes at all…that makes ME nervous. ( Eyes should be freely given, too.) For FREE. It’s “hard work” to do it yourself. But, I guess it helped.

    Money,money, money, money…what makes science any different from woo in this respect?? They all ask you to BELIEVE without question.

  37. Hilary April 25, 2011 at 09:49 #

    What about informed consent or even assent? Surely it is cruel to inflict this intervention on children who have no choice in the matter. It sounds scary enough to me as someone mildly claustrophobic, must be horrific for an autistic child.

  38. McD April 27, 2011 at 03:23 #

    You can’t patent oxygen?

    So THAT’s why there is no research supporting HBOT around. Nothing to do with no lack of a plausible causal mechanism and all that other mumbo jumbo that big pharma put out to mollify people.

    It’s a good thing that one can still make oodles of money out of the delivery mechanism, and those CAM heroes are able to do something about my boy’s oxygen-deprived temporal lobes, providing I can get a second mortgage on the house.

    Has anyone noticed an increase in the number of kids with autism at high altitude? If there is anything to HBOT there should be a correlation – there should be autism clusters at high altitudes. IIRC clusters may actually be correlated with freeways – if anything.

    Thoughtful House throwing HBOT under the bus is interesting as well.

  39. McD April 28, 2011 at 01:37 #

    Laurent said: “Reading T.Grandin you can understand that old (and rigid) education is highly consistent for kids with autism. But there is no money promoting old education. For money makers, ABA seems a better way.”

    Might need to re-read Temple then. Her very wealthy family could afford a governess who kept Temple engaged in constructive activities and appropriate behavior throughout her waking hours. Temple has described this as about as close to intensive 1 on 1 behavior therapy as you could get those days (both in her books, and in a discussion I was party to on one occasion – she directly compared the training her governess gave her to ABA). Modern ABA is not rigid, it is very responsive to the child.

    And as Rose has pointed out, don’t confuse the method with the delivery mechanism (bit like oxygen – you can breathe it in yourself or get HBOT). Many parents have set up successful programs for their own kids. But it is hard work.

    • Sullivan April 28, 2011 at 14:27 #


      I agree, it is hard work to try to be both therapist/teacher and parent. Not the least of which is just balancing the roles. To use a bad analogy, it’s like trying to be a manager and just one of the guys at different times of the day.

  40. Sniffer April 28, 2011 at 12:05 #

    Dear Mc D

    “delivery mechanism (bit like oxygen – you can breathe it in yourself or get HBOT).”

    I would suugest you broden your reading to You Tube and you can see the administration of HBOT and pressurized oxygen ,and the cures and benefit.



  41. Prometheus April 28, 2011 at 17:08 #

    Mr. Betts,

    I appreciate your restraint in not wanting to start any “flaming diatribes”, but I have a few questions. I’ll try to contain my grief if you feel obligated to reply in “flaming” fashion.

    Would you happen to be the Edward Betts who is the president of Pressure-Tech, Inc of Freeport, NY? The same who received an FDA Warning Letter about your hyperbaric chambers on 4 September 2009?


    Are you also the co-founder and executive director of ANDI? Your bio on the ANDI website describes you as a “practical engineer” – I assume that means you have no formal education in engineering.

    I also note no mention of credentials in biology, medicine, physiology, etc. I assume that means you also lack any education in those fields. Your sole qualification in HBOT appears to be that you owned a scuba shop and now own a company that makes hyperbaric chambers.

    So, you have a significant financial interest in promoting the “off-label” use of HBOT, have been reprimanded at least once by the USFDA for failing to follow regulations concerning the manufacture and sale of HBOT chambers and have no education in the fields in which you claim expertise. Is that correct?

    Also, the article by Dr. Markley doesn’t appear in any index of scientific publications, leading me to suspect that it either hasn’t been published (on paper) anywhere or has been “published” only in a trade journal or advertising circular.

    Let’s say I’m not convinced and leave it at that. I’ll assume that any “flaming diatribe” will indicate you have no cogent reply to my questions.


    • Sullivan April 28, 2011 at 21:37 #


      why am I not surprised? The approach for HBOT appears to be, “we have a hammer. I wonder if autism is a nail”, rather than, “here’s what we really think is going to happen with HBOT.

  42. Sniffer April 28, 2011 at 20:04 #

    Prometheus anyone with Mr Betts qualifications as you imply, is more than qualified to use a hard chamber never mind a soft chamber in the UK.

    Why would you need to have a lot of corrupted medical qualifications from the University of Pharma Satin just to operate HBOT. Forgot the oxygen works and we can’t have Pharma losing out on no cure, hope drugs.

    Why attack Mr Betts ?Why not just talk about the subject matter? I say, you are off topic.



  43. Pearmtn May 10, 2011 at 12:20 #

    Dear Prometheus,

    How do you respond to the verifiable experiences and observations of the parents of autistic children, the attending physicians, etc., who attest to the real benefits derived from HBOT via Blogs and YouTube videos available for all of us to read and see. These testimonials have been available for years! Are they delusional, are they spreading falsehoods deliberately, WHAT Prometheus can possibly be the explanation?

  44. steve veloso May 29, 2011 at 04:18 #

    Oxygen is not flammable or combustible, flammable and combustible gasses are harmful to humans when inhaled.
    Oxygen however supports combustion and anything flammable, it is a key component, more like a catalyst to burning. This is being taught in chemistry 101.
    Whenever I hear somebody says Oxygen is flammable or combustible I think about that person as being ignorant and a charlatan.

    • Sullivan May 29, 2011 at 04:30 #

      steve veloso,

      somewhat accurate, but not really informative.

      Here’s a counterexample–hydrogen is not flammable. In the presence of oxygen, it is. I’ve never seen anyone complain about a “flammable” sticker on a hydrogen bottle.

      There are materials which are flammable in a pure oxygen environment which are not flammable in air.

      You misunderstand the term “catalyst” by the way. Perhaps you could pull out your chemistry 101 book before you start to lecture. A catalyst is a substance which is not consumed in the reaction. For example, the rhodium in your catalytic converter. Oxygen is clearly consumed in a reaction involving burning.

      “flammable and combustible gasses are harmful to humans when inhaled.”

      Not a technical diver, are you?

  45. steve veloso June 17, 2011 at 18:54 #

    I did not said it is a catalyst, I said and I quote
    “more like a catalyst” I use this term “more like” to get down to lay man’s terms.
    the links you provided confirm the harmfullness of these flammable gasses, thanks. 😉

    • Sullivan June 17, 2011 at 22:53 #

      steve veloso,

      Your understanding is lacking. It is not “more like a catalyst”. The links I provided may confirm a notion you have for you. If that somehow puts your mind at ease, that’s fine. But you are incorrect.

  46. steve veloso June 17, 2011 at 19:04 #

    Sullivan, you said: Here’s a counterexample—hydrogen is not flammable. In the presence of oxygen, it is. I’ve never seen anyone complain about a “flammable” sticker on a hydrogen bottle.

    true, but we are talking about oxygen, which still holds true that it supports the combustion of hydrogen.

  47. Chemmomo June 18, 2011 at 16:39 #

    steve veloso
    re: “Oxygen however supports combustion and anything flammable, it is a key component, more like a catalyst to burning. This is being taught in chemistry 101.”

    No, this is NOT taught in Chemistry 101.

    The definition of combustion is reaction with an oxidizing agent – often oxygen.

    Oxygen is a reactant during combustion. Not only is it consumed during the reaction, it is incorporated into the products of combustion – absolutely nothing like a catalyst, which by definition is present at the end of the catalytic cycle.

    If you can’t distinguish between a reactant and a catalyst, you have no business lecturing anyone on this topic.

  48. steve veloso June 19, 2011 at 06:53 #

    sullivan, To you “more like” = “like” which is entirely different.
    let the readers decide for themselves who is correct and who is not. My comments may not be correct to you but that is your opinion and it is only incorrect to you. This is the beauty of the internet, the true and the false are all here with discussion on who is right and wrong, it is up to the readers to decide for themselves.

  49. steve veloso June 19, 2011 at 07:01 #

    Chemmomo, It was thought in my chemistry class 101, maybe not in your class.
    again it depends on your understanding of what “more like” means, I have explained my concept of “more like” which differs from “like”.

    I just hope the readers on this page does not agree with your reasoning else they will be wrong when they answer an IQ question of does oxygen supports combustion?

    and this is not a lecture, this is a discussion. which would the readers believe? you or some guy in Phd who wrote the book, published and being used in universities?

  50. Chemmomo June 19, 2011 at 22:17 #

    steve veloso,
    It doesn’t matter what you think “more like” means. Your statement is in fact incorrect, and no amount of qualifying it will make it correct.

    During a chemical reaction, such as combustion, reactants turn into products. In a catalyzed reaction, the same reactants still become the same products, but the catalyst causes the reaction to occur more readily, and is present at the end of the catalytic cycle in the same form as it was before reaction began.

    “Oxygen supports combustion” because it is a reactant.
    For example, the combustion of propane:
    C3H8 + 5O2 goes to 3CO2 + 4H2O

    All of the oxygen is consumed. It is NOT a catalyst.

    Why do you assume that I don’t have a PhD and haven’t written a book?

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