Hello from Kansas

[Lim]

Yes medical compression chambers are used to treat none diving conditions. In fact, most UK diving related decompression incidents are treated by chambers in hospitals. The difference is if the patient has a O2 event (hit) they’re not going to drown. An O2 hit is instantaneous unconsciousness, in the water you will drown.

As there are no bubbles with a rebreather any surface cover wouldn't know if anything was wrong. On open circuit you'd be too deep for the surface cover to get you out in time.

A Darwin award in the making.

I see where you're coming from, I really do. And I appreciate your trying to keep me from from injuring or killing myself.

This is why I think about things like:

1. slightly negative buoyancy
2. suspending myself from a rope, from a buoy with enough positive buoyancy to hold me in place (I may need still water to avoid an upset, so probably a lake in the tropics is safer than ocean)
   
3. small weights on my feet
4. a bucket over my head, tied down to my weight belt.

Effectively a mini personal diving bell.

Zero visibility, but since this is not really a recreational dive, but a new category, I can do things like that.

I think by now I've abandoned the DIY oxygen rebreather idea. If I can get O2 and go to 17 feet, the risks are easier to quantify. Open circuit. Bubbles. No caustic soda lime.

 

[Lim]

I have nothing to add just a question. What symptoms are you having that you are trying to treat with this?

That's a really good question.

If you don't mind my saying so, I am not eager to get too deep into it here. Bottom line may be: Can I learn well enough, and think quickly enough on my feet, and avoid passing out or seizures -- so that it's safe for me to dive, at least within normal scuba parameters? Yes. Not only that, my doctor already has cleared me for, and even suggests, 40 hours of the oxygen at 1.5 ATA that the scuba community avoids due to its risks. That means she doesn't think I'm at risk of seizures. Certainly I've never had one yet.

The cognitive issues that beset me only keep me from performing at the elite level at which I formerly did. This is like a "first-world problem" but it has a cascading effect that you might not initially guess:

Potential employers who look at my resume don't call back when I apply for jobs. They surely think "if he graduated from X and worked at Y, then why is he trying to get an entry level job as a retail grocery clerk?" After some years of that (during which I burned up all the savings from my original career), if I just leave large resume gaps, they probably assume "he must be a junkie or have been in prison or something."

I've realized the world doesn't want me as I am. I couldn't even get a grocery store job until, after many years, I finally started to lie (which I hate; it's humiliating; truth is my highest value) and say I'd been hauling stuff around in my trailer for people, for the last umpteen years.

In 2017, when I finally was referred to a neurologist, the referral listed a diagnosis of "somatization disorder," which reads a lot like "hypochondriac; please don't be too curious about this guy." Unsurprisingly, when my verbal performance scored as "only one standard deviation below average" (seems like I don't process language as quickly now) he thought that was just fine, never mind that my verbal faculty used to be my strongest one, three standard deviations above average. So this guy chose to ignore a cognitive decline of four standard deviations. That's just fine with him! As long as he wasn't involved in causing that, right?

I have been diagnosed with chronic PTSD. (My kind, complex PTSD, comes from prolonged situations rather than discrete major events.) Based on this, my doc, after knowing me for 3-4 years, seeing my sporadic* employment, suggested I apply for Disability. But the Social Security Administration said "no, you seem able to advocate for yourself" and rejected my claim.

*One issue is that boredom is stressful, and since I have PTSD (not from big events, but from continual situations in which I was obligated to remain), a job wears me down (as did being married with stepkids). If I keep working in grocery stores, for a few months at a time as I'm able, I am likely to end up dead, of boredom and the things that desperately bored people do. Case in point, perhaps.

Scuba may also have some benefit for PTSD, according to another study.

I also have a mysterious inflammation in my jaw, which doctors cannot detect because I am so good at self-medicating. Medicaid doesn't cover naturopaths where I was, so the docs I could see don't get trained on the fact that some herbs are antibiotics, and thus they think "his condition is controlled adequately by *nothing*" and infer "his condition is imaginary." I'm the only one who knows what happens when I get a weak batch of herbs.

HBOT is surely worth $8K if it really would restore my mind and career to their original lustre. It's just that it's such a long shot. I've spent tens of thousands, when I used to have money, on various treatments that did not work. I feel cynical about it as a purchase. Anything that's a gamble is disocunted accordingly. It's a lottery ticket, so it should be priced like one. Supply & demand is an invidual thing; price discrimination is a thing because the poor have time & motivation to find cheaper options. Necessity the mother of inventions...

Maybe, since many things are cheaper in the developing world, I could find medical HBOT there. I should look into that. But I know that I will be seen as a gringo to be milked for his cash. (Fair enough. Since gringos have inserted themselves between the developing world and its resources, folks have to get it back however they can.)

Some people have their own hyperbaric chambers at home, but likely their fear of liability keeps them from sharing them. So we get people like me trying to DIY it and solo at that.

I am also looking into renting a chamber to have at home, but there is not much room at home. I'm staying with a friend who's a hoarder. I would have to build a "bunk bed" platform and have the chamber over or under my bed. And it would only go to 1.3 ATA. Frankly that sounds like a lot of work that would make me feel even more like a shabby sick person. I think i would boost my morale if I can manage to heal myself. And if I die trying, that's fine. I don't have kids, and I'd rather die with enough money for a funeral.

For me, injury is much worse than death, but I do have health insurance for an emergency, though only for an emergency.

 

[broncobowsher]

Normally I see one of these greetings from Kansas post and it's someone realizing that the Midwest doesn't really have any good diving opportunities.

Reading through the idea of discount hyperbaric medication, I'll just put this out there right now for when there is a court case and someone goes looking for history of what happened...

Don't do it.

High pressure oxygen in a dry environment isn't the same as a wet environment. Pressure may be comparable, but that is about it.

And to go back a page or so, from where you are at now to being certified for a rebreather, about $2k in training. Not many people do it. Very specialized. Given your background and why you want to do it, nobody will teach you.

 

[Lim]

Normally I see one of these greetings from Kansas post and it's someone realizing that the Midwest doesn't really have any good diving opportunities.

Reading through the idea of discount hyperbaric medication, I'll just put this out there right now for when there is a court case and someone goes looking for history of what happened...

Don't do it.

High pressure oxygen in a dry environment isn't the same as a wet environment. Pressure may be comparable, but that is about it.

And to go back a page or so, from where you are at now to being certified for a rebreather, about $2k in training. Not many people do it. Very specialized. Given your background and why you want to do it, nobody will teach you.

Ah, finally. Thank you. I appreciate when people actually answer the question I asked. That's what I wanted, a number. $2K is a lot less than $8K and opens up a lifetime of adventures rather than another just drab sad "professional sick-person" experience that makes me want to die.

I get that for (almost) everyone but me, the most important thing is liability, not my health or whether I can have a life worth living. Fair enough. You do you.

 

[Edward3c]

Ah, finally. Thank you. I appreciate when people actually answer the question I asked. That's what I wanted, a number. $2K is a lot less than $8K and opens up a lifetime of adventures rather than another just drab sad sick-person experience that makes me want to die.

I get that for (almost) everyone but me, the most important thing is liability, not my health or whether I can have a life worth living. Fair enough. You do you.

I didn’t give you a price for training as it varies so much. Although the course might be $2k the work to get up to pre-course standard will cost a small fortune with equipment, gas purchases, travel and accommodation costs.

 

[Lim]

When I said "digital nomad," I meant living in some place that's even cheaper than where I live now. It's an idea popularized by Tim Ferriss in his book /The 4-Hour Workweek/. The whole premise is exploitation of the income differential and cost differential (e.g. apartment via Airbnb costs $300/month) between the "developed" and "developing" nations. I hate it, but then again there isn't much about modern life that I don't hate. It seems like hypocrisy is mandatory.

Even if I do spend the $8K, I might rather spend it on something fun than for the privilege of spending 40 hours in that clinic. Frankly, at this point maybe the biggest threat to my health and life is that my life is excruciatingly boring, a fate which some have deemed worse than death.

One of my closest friends, the welder, was really excited for me about this whole idea.

You know, I may just stick with normal scuba. I just read that regular air at 1.2 or 1.3 ATA (used as the "sham" control in some studies) may be as therapeutic as pure oxygen at 1.5 ATA: Hyperbaric oxygen therapy for post concussion symptoms: issues may affect the results | Medical Gas Research | Full Text

I can get to 1.2 ATA in 7 feet of fresh water! And a local dive shop has a pool -- although it is open only one day a week, if COVID even permits that. This is also good practice for a person whose Open Water Diver certification hasn't been used recently -- right?

 

[Lim]

Thanks to all who've replied. I showed this thread to my friend who welds, and he just wrote me this:

Read the string – could be the beginning of a new novel complete with honesty, pathos, indignation, humor, sadness, you name it. Very open and frank, and you found at least 3 people who care about others (as well as their sport), at least in an abstract sense…

Darwin award…priceless!

Normal scuba – brilliant idea finally. ****-can all the fancy equipment crap, stop worrying about the potential for oxygen hits (learned a new term) and dissolved lungs. Go to Ecuador or Costa Rica (Mexico maybe), lie in the sun, scuba, eat seafood, get well!

Since you didn’t ask for it: my opinion – you’re making complex out of simple. Life is one foot in front of the other, regardless of “planning”…

 

[tmassey]

My near-term goal is a DIY form of hyperbaric oxygen therapy (HBOT). My doctor has prescribed HBOT to help recover from concussions I had many years ago. Rather than pay $8,000 (nearly all I own) for 40 HBOT sessions in a clinical setting (5 days a week for 8 weeks) or spend money on more dumb health-related equipment (yes, people have hyperbaric chambers at home, even build them inside propane tanks, but I already own so much get-healthy gear), I thought I might be a digital nomad near warm ocean water for 2 months.

You reject the perfect tool for the job (hyperbaric treatments in a medical setting). You reject a lesser version of the right tool for the job (home hyperbaric chamber, DIY or otherwise). You'd rather shoehorn the wrong tool for the job (underwater hyperbaric O2 exposure) because "I already own so much get-healthy gear". That alone is a *massive* red flag. SCUBA is *nothing* if not equipment-intensive.

As you've noticed, achieving elevated PPO2 as part of a SCUBA dive comes along for the ride. As divers, it has been found that there is a non-zero chance of death associated with that elevated exposure to O2, and as divers approach and exceed an exposure of 1.6 that risk elevates in an unpredictable but clearly negative way.

Your level of ignorance here is *stunning*. Ignorance, in and of itself, is fine: you have to start somewhere. But the way you have approached this has made it all but impossible to answer in a way that doesn't scream 'severe legal liability'. I'm not surprised at all by the reaction. Besides, virtually none of us are medical practitioners, and those that are aren't going to deviate from the answer you've already been given!

But, leaving *all* of that behind, how about this question: can you dive with enhanced oxygen dive gasses safely? Can these dives be done effectively and affordably? Yes. #1: do a SCUBA refresher. I too was certified in 1992. The basic mechanics haven't changed, but dive science has advanced a *LOT* in 30 years..... Next: take an Enriched Air Nitrox class. It will teach you many of the things you need to know, including how to safely plan and execute such a dive. Cost of these two? Probably in the neighborhood of $500 to $1000, especially if you own zero gear.

Once you have the knowledge and understanding found in a quality version of those two classes. the answers to your questions will be blindingly obvious. And you may, in fact, be able to come up with a procedure that is both safe and delivers what you are looking for.

Few people are going to recommend a PPO2 of 1.6, but 1.4 is within most organization's standards, with 1.6 used as a contingency factor. And, despite the responses you've gotten, if you were willing to work with a PPO2 of 1.4, and assuming that your desired level of exposure to that pressure is measured in minutes (say, 60), and if you could divide it into two parts (such as a 2-tank dive), it might even look very much like dive profiles that people who replied are already doing on a daily basis!

But like your welder friend implied (though not as tongue-in-cheek as he intended it): please do not disrespect the time and effort we have put into learning and practicing a dangerous recreation safely by asking us about 'putting a bucket on your head and sucking welding tanks at the bottom of a pool'. We care about ourselves, our buddies and our recreation as a whole. Please don't disrespect what is involved, even if it clearly comes from great ignorance.

 

[Lim]

What you say's very relatable.

You reject the perfect tool for the job (hyperbaric treatments in a medical setting). You reject a lesser version of the right tool for the job (home hyperbaric chamber, DIY or otherwise). You'd rather shoehorn the wrong tool for the job (underwater hyperbaric O2 exposure) because "I already own so much get-healthy gear". That alone is a *massive* red flag. SCUBA is *nothing* if not equipment-intensive.

As you've noticed, achieving elevated PPO2 as part of a SCUBA dive comes along for the ride. As divers, it has been found that there is a non-zero chance of death associated with that elevated exposure to O2, and as divers approach and exceed an exposure of 1.6 that risk elevates in an unpredictable but clearly negative way.

Your level of ignorance here is *stunning*. Ignorance, in and of itself, is fine: you have to start somewhere. But the way you have approached this has made it all but impossible to answer in a way that doesn't scream 'severe legal liability'. I'm not surprised at all by the reaction. Besides, virtually none of us are medical practitioners, and those that are aren't going to deviate from the answer you've already been given!

But, leaving *all* of that behind, how about this question: can you dive with enhanced oxygen dive gasses safely? Can these dives be done effectively and affordably? Yes. #1: do a SCUBA refresher. I too was certified in 1992. The basic mechanics haven't changed, but dive science has advanced a *LOT* in 30 years..... Next: take an Enhanced Air Nitrox class. It will teach you many of the things you need to know, including how to safely plan and execute such a dive. Cost of these two? Probably in the neighborhood of $500 to $1000, especially if you own zero gear.

Once you have the knowledge and understanding found in a quality version of those two classes. the answers to your questions will be blindingly obvious. And you may, in fact, be able to come up with a procedure that is both safe and delivers what you are looking for.

Few people are going to recommend a PPO2 of 1.6, but 1.4 is within most organization's standards, with 1.6 used as a contingency factor. And, despite the responses you've gotten, if you were willing to work with a PPO2 of 1.4, and assuming that your desired level of exposure to that pressure is measured in minutes (say, 60), and if you could divide it into two parts (such as a 2-tank dive), it might even look very much like dive profiles that people who replied are already doing on a daily basis!

But like your welder friend implied (though not as tongue-in-cheek as he intended it): please do not disrespect the time and effort we have put into learning and practicing a dangerous recreation safely by asking us about 'putting a bucket on your head and sucking welding tanks at the bottom of a pool'. We care about ourselves, our buddies and our recreation as a whole. Please don't disrespect what is involved, even if it clearly comes from great ignorance.

That is a very relatable point of view.

Mine is that I'm accustomed to suffering for decades when I trust and follow the advice of certain professionals. The only measures that have improved my health have been things I researched myself and sought out, only possible because I started to read the real journals 18 years ago. The psychiatric diagnosis I ended up with, I got it by asking for it, after I researched it.

If you think I exhibit disrespect for scuba divers, wait 'til you see what I think of medical doctors! There are a few good apples, but that doesn't change that it's a guild.

On dive medicine, it's easy for me to trust the Navy, for a reason: Their physicians and scientists are not working on a fee-for-service ("let's see how many hours I can spend solving problems") basis and are not beholden to insurance companies.

Hearing all the risks, sorting them from greatest to least, and addressing them one by one, in a continual iterative process... That's an engineering process. It's not intended to insult anyone. It's just that I'm an engineer. And I'm new to this application domain, so I can only throw out some suggestions and see what reaction I get. Please don't take offense.

I still have my gear from 1994 and have a wetsuit I bought in 2013. Just to dive with regular air at 7 feet, I would not need a lot more gear. I'd need just one 80cf tank with air in it. Well, I need to replace my BCD too.

If my physician believed that scuba were as effective (for reversing 30+ year old concussion damage) as HBOT, she might have told me, but it became less likely after she'd bought her HBOT equipment.

Even professionals are humans. People believe what they want to believe. My doc does. I do, too. This is why the placebo effect may be the most important factor in healing (usually it's at least half the total effect in any study), which is part of the reason why doing it my way -- not necessarily the one I invent, but the one that I believe in -- is important and may improve the results.

I have decided that, realistically, for merely-hypothesized concussions 33 and 31 years old, it would be pretty hard for me to believe that even 8 weeks of intensive HBOT therapy, recommended to me by a physician who's shown a disregard for well-regarded evidence, would suffice to put Humpty Dumpty back together. Most doctors have said that's usually not how chronic disease recovery works. More likely, if one is sick for N years, then it may take on the order of N years to get well. If lucky, somewhat less--maybe a year or two, if very lucky. But not 8 weeks.

Now I feel inspired. Maybe I will even "move" (most of my stuff is in storage anyway) for a least a year or two, to somewhere with better diving. I mean real diving, worth doing for fun, because I feel that just sitting at the bottom of a pool breathing regular air at 7 feet for an hour a day, eventually would feel like more of the same "sad pathetic professional-sick-person" lifestyle that has made me so bored of life. But I think I've found plausible reason to believe that just doing "normal" scuba could be better, for me, than $8,000 worth of medical therapy. Their own literature supports this idea.

Thanks for giving me some specifics rather than only telling me the obvious, that I'm ignorant, arrogant (I am among the most arrogant people I know) and rude. Sounds like your info is consistent with the conclusion that I eventually hit upon, after all that discussion: No need for buckets, etc. But the reason I don't need a bucket or medical/welding oxygen is that I got new info from the medical side about what's required -- and found that, if they are correct, it is well within entry-level divers' reach. Just regular air at 1.3 or even 1.2 ATA could move me in the direction of health.

If it's going to take years, which is the conventional wisdom for chronic health problems, the treatment needs to be safe(-ish) and cheap(-ish), like normal scuba. Can I afford $80,000 worth of HBOT sessions if it takes me 80 weeks, which is quite possible? No.

I have edited my initial post to tell people "don't bother" so that hopefully I don't upset everyone reading it.

 

[duke dive medicine]

I took a PADI Open Water Diver course in 1994, when I was 21. I did a small number of dives that year and haven't since. I'm 47 now. I used to be an engineer, but most recently I've been a substitute teacher. My hobbies are mostly DIY, and scheming how to DIY everything, especially expensive things -- motivated by social justice concerns.

I'd like to get back into diving, perhaps very soon. Today I enrolled in a "ReActivate" course online.

[Edit 12/31 2:41PM: Never mind the rest. Near the end of the thread, my ongoing review of medical literature showed me that just normal everyday scuba situations accessible to the entry-level OWD certified -- or even less PPO2 than in a typical dive -- may be just as therapeutic as the more dangerous high-PPO2 ones. I mean, like normal air at only 1.2 ATA -- i.e. 7 feet depth.]

I have edited this a bit to clarify what I'm asking. I'm not trying to make it look like the first few respondents didn't read it.

Are you one of the few who are into "harm reduction?" If not, I get it, feel free to tune out, because this will be analogous to helping junkies find clean needles and naloxone.

I think I've already read about all the things that can go wrong. On the other hand, what's going most genocidally wrong in the modern world is that too few can afford the healthcare (or anything else they need) when provided through the parasitic gate-kept system of artificial scarcity. Scuba is somewhat of a luxury sport, I get it. But I'm not posh, I'm punk.

So I can assure you that all of my ideas are bad and dangerous, but maybe someone can help me identify the "least worst" of them before I choose randomly. Again, harm reduction.

My near-term goal is a DIY form of hyperbaric oxygen therapy (HBOT). My doctor has prescribed HBOT to help recover from concussions I had many years ago. Rather than pay $8,000 (nearly all I own) for 40 HBOT sessions in a clinical setting (5 days a week for 8 weeks) or spend money on more dumb health-related equipment (yes, people have hyperbaric chambers at home, even build them inside propane tanks, but I already own so much get-healthy gear [I mean professional-sick-person gear, not sporting gear]), I thought I might rather be a digital nomad near warm ocean water for 2-3 months.

Specifically, in the near term, I'd like to get trained and equipped to breathe -- one way or another -- oxygen at 1.5 ATA for an hour a day, 5 days a week. So that's either pure oxygen at 17 fsw or, less likely, nitrox at a deeper depth.

Nitrox: Even after I've taken the Enriched Air Diver course, would dive shops sell me nitrox with enough O2 to do what I want? No, right, not without additional courses to dive deeper?

Since you know that I am definitely not going to spend $8K on professional hyperbaric oxygen therapy, what might be the least-worst path to be trained adequately (from a scuba perspective, not a medical one) for the situation I'm trying to create?

How about the Rebreather Diver course?

Can one rent a closed-circuit oxygen rebreather?

"Do you also want to actually dive for recreation?" you may ask. Yes, I do. I am interested in, especially, underwater photography of wildlife, and exploring shipwrecks, eventually. But for now, I could be anywhere.

But I don't much like cold, or dark. I haven't lived near warm water (over 80F) since that one summer in 1994. And I am quite frugal, so I could not justify more training in diving until I saw a health benefit to it also. But Ecuador is fully open despite COVID and I could fly there for $250.

Would appreciate any suggestions.

Here are some more-frugal ideas, the type of dangerous ideas that will continue to appeal to me until you tell me something more specific than "don't do any of that stuff and just pay the $8K."

Yes, I know I can buy oxygen for welding. They'd fill a steel tank, $30 for 80 cu ft at Praxair. Even industrial gas suppliers have said it's the same as medical oxygen; the only difference is in how the rinse out the tank. I could provide my own brand-new tank and insist on getting that one back. Surely I could buy or build an adapter from CGA540 to a yoke. I'd need a regulator and valves cleaned for oxygen.

Yes, I know one can build an oxygen rebreather. Many have done it, and they've all said "kids, do not try this at home." But it's definitely do-able, for $100-ish. That's DIY in a very punk sense. How does it compare to riding a motorcycle daily? Some sports are dangerous. Just don't call it scuba and give scuba a bad name, right?

I still am hoping to do it in the least-worst way, which (since I have ruled out the clinic) normally in the scuba world would mean that I get properly trained and then get outfitted by a responsible scuba shop. Except that almost nobody in the scuba community wants to have "encouraged" me, right? Most would rather leave me to fly completely solo? Like junkies with their dirty needles? Perhaps almost everyone is against needle exchange programs. But only almost.

More things you need not say:

"Even at 1.5 ATA there's some risk of seizure, more than at 1.3 ATA." I don't want to lose my mouthpiece, get water into my caustic oxygen absorber, inhale that, and die with dissolved lungs. Nope. You need not say "take magnesium or other anti-convulsant, and isn't it good that you've never had any seizures before," since I asked for scuba harm-reduction, not medical advice.

Seems like, in the end, doing this with welding oxygen, without the aid of any dive shops, may be the least-worst way for me in the near-term, especially if a major goal is to avoid risking anyone in the scuba community feeling bad about having told me to shoot myself in the -- I dunno, hand? -- instead of the foot.

But really, someone might just tell me to take the rebreather course, right? (Someone could, not just anyone could. The Dalai Lama says that if you must eat meat, at least don't kill it yourself; but others believe the opposite, that if you must eat meat, at least do kill it yourself. And in social justice and war, some are neutral, while Archbishop Desmond Tutu said that neutrality is tantamount to siding with the oppressor.)

Also, what gear might reduce the risk, in case I did have a seizure? A full-face mask? A helmet? You know, so that I keep breathing if I lose consciousness. If nobody recommends an affordable one, I may just improvise something you'd consider totally goofy and unsafe. How about a bucket over my head, as a diving bell? And extra weights on my feet, to keep me vertical? I don't care how goofy I look.

Ultimately there's no complete safety in life, is there? A poor person could die of an antibiotic-resistant infection, or cure it with DIY HBOT, or die trying... the main difference may come down to whether people on the sidelines get to feel good about themselves according to their chosen moral codes. To each his own!

Hope it's okay to discuss this stuff here. To be clear, I'm asking for scuba harm-reduction advice, not medical advice. (I am only an engineer, but I have been reading real peer reviewed medical literature since my doctor challenged me to, in 2002. I will also ask my own doctor, who will say "just give me the money" to her dying breath.)

Here, as an afterthought, are examples of suggestions that might actually save my life while not beating your head against a wall (since I am going to go some kind of DIY route and not pay the $8,000):

Someone might tell me things like:

• "Find a friend. Have them watch you."
• "Olympic diving pools are 16 feet deep."
• "Maybe someone has a hand-dug well on their farm or ranch."
• "Wear a harness, so that the buddy can pull you up on a rope."
• "Build your own hyperbaric chamber. I did."
• "Please use my hyperbaric chamber before you DIY your own; it's tricky."

Anything along the lines of "just pay the $8,000" I will ignore. My net worth is hugely negative, I have no credit, and $8,000 is about all I have. It's DIY or die. Or maybe DIY *and* die, but die trying. I will be darned if I pay all I own to that doctor -- who 100 years ago would have offered a sliding scale, but now thinks she can't -- on the strength of a study that probably hasn't even been replicated adequately. (Heck, my doctor also suggested EDTA chelation for vascular disease, even after the TACT failed to show significant benefit for anyone other than diabetics -- and I'm not diabetic.)

Hi @Lim ,

There is some evidence to suggest that hyperbaric oxygen therapy can be of benefit for post-concussive symptoms, but at the risk of second-guessing someone who has examined you in person, you're pretty far out from the injury and its relationship to your current symptoms seems a bit tenuous.

You've probably figured out already that there's a big therapeutic difference between getting 100% oxygen at twice atmospheric pressure in a dry hyperbaric chamber and diving nitrox to an inspired partial pressure of oxygen (pO2) of 1.4 atmospheres absolute. It is dangerous to the point of foolhardy to try to duplicate true hyperbaric oxygen therapy under water; the risk of CNS oxygen toxicity is much greater when you're immersed. But, if you can get medically cleared to dive, why not take a nitrox course and go diving? If you're looking to breathe O2 at > 1 atmosphere absolute, you can do that and still stay within the recommended safe limits of nitrox. I would strongly recommend that you not exceed those limits though.

Best regards,
DDM