Dry Hypoxia Training for Rebreather Divers

Have you ever done an intentional dry hypoxia exposure?

  • Yes, monitored by a professional in training.

    Votes: 7 8.0%
  • Yes, at home with a friend.

    Votes: 8 9.1%
  • Yes, but as a part of an aviation training course.

    Votes: 2 2.3%
  • No, but believe that it might be useful for rebreather divers.

    Votes: 51 58.0%
  • No way, you kidding me?

    Votes: 23 26.1%

  • Total voters
    88
I have some trouble understanding the things you write, but do I understand you correct when you compare the things Dave suggested in the beginning of this thread with breathing pure nitrogen?

If Im understanding that correct you two are speaking about two totally different things.
Hypoxia has a lot of character, may be slowly increasing, it may be rapidly growing. Could be due to stress caused rapid compression.
Training only weighty range of possible causes of hypoxia gives poor odds. Especially the lack of intellectual ability also causes ppN2. Clinical tests have been known for many years, they were done on both sides of the cold war.
I hope this is just a bad translation, because this is just rude!
Gents:

I am going to close this thread unless some subject is articulated *very soon* that is comprehensible to the readers.

Start by writing something that *I* can understand. I'm a smart guy.. write something that is not gibberish.

Is there a question or a statement being made here? One or the other is a requirement for further discussions. Failing a clear statement, or a clear question, with a clear objective, it's at it's end.

Failure to sense the pulse of the ethos here and to participate with clarity as a member of our society will result in a hammering... :crash:


Am I making myself clear?


Carry on,


Dave


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Espacenet - Quick search

Persons or organisations

Check authors: Kevin Gurr, Martin Parker, BUEHLMANN PIERRE, Imre Botos, Ryszard Czarnecki, Dave Sutton.

greet rc
 
More threats eh Dave..

Wow that's just not cool.

If you can't answer questions please don't respond with such violent rhetoric as promising "hammerings".
 
Hypoxia has a lot of character, may be slowly increasing, it may be rapidly growing. Could be due to stress caused rapid compression.
Training only weighty range of possible causes of hypoxia gives poor odds. Especially the lack of intellectual ability also causes ppN2. Clinical tests have been known for many years, they were done on both sides of the cold war.

Espacenet - Quick search

Persons or organisations

Check authors: Kevin Gurr, Martin Parker, BUEHLMANN PIERRE, Imre Botos, Ryszard Czarnecki, Dave Sutton.

greet rc

I don´t understand at all what you want to say.... :(
 
What is the hypoxia caused by rapid compression?
What is hypoxia after exposure to oxygen ppO2 3ata?
...
Which of the following, has nothing invented in diving equipment?

greet rc

That is just three more questions and no answers.

What does your three questions have to do with testing this in a CCR course? Breathing from a loop with no O2 injection.
I have never done one test during any course that has given answers to everything, but it have given me a tool of understanding little more how it could be or work.

Do you think everything should be included in one test?
 
Do you think everything should be included in one test?

If the test proposed by Dave restricted to slow progressive hypoxia, its usefulness is small.
Diving has more factors that complicate the picture hypoxia.
The physiological responses also can be surprising.

It has not been studied in high efforts.
It has not been tested with the masking effects of high ppN2.
It has not been tested with the masking effects of high ppHe.
It has not been tested for pure inert gas.
It has not been tested in a rapid compression.

greet rc
 
If the test proposed by Dave restricted to slow progressive hypoxia, its usefulness is small.
Diving has more factors that complicate the picture hypoxia.
The physiological responses also can be surprising.

It has not been studied in high efforts.
It has not been tested with the masking effects of high ppN2.
It has not been tested with the masking effects of high ppHe.
It has not been tested for pure inert gas.
It has not been tested in a rapid compression.

greet rc

But please tell me why that has anything to do with the tings Dave suggests?
The test is not a holistic test were you get all answers. That test doesn´t exist.
From the test you get an understanding how it can feel like, you don´t get to know how it feels in every situation but you get little more sense in how it can feel.

Knowledge like that is good even if it can variate i different situations.
Is your opinion that it is better to know nothing than little?
 
What is the hypoxia caused by rapid compression?

I don't know?
Surely as you go down... PP02 goes up. Hypoxic event caused by equipment would be apparent on steady depth or on ascent.

You saying rapid descent can cause hypoxia? How?
How rapid the descent? The sort of descent routinely done?


If hypoxia is caused by exertion this is not the purpose of this exercise, purpose of this exercise is to increase the chances of you seeing signs yourself that there is some equipment failure reducing inspired PP02.

I don't see why breathing purely inert gas is relevant. You will be on your arse within seconds and it is not likely to happen, unless you hooked up your suit bottle to dil or something else silly.
 
I don't know?
Surely as you go down... PP02 goes up. Hypoxic event caused by equipment would be apparent on steady depth or on ascent.

You saying rapid descent can cause hypoxia? How?
How rapid the descent? The sort of descent routinely done?

#171 (permalink)

greet rc
 
Is your opinion that it is better to know nothing than little?
What is the sense of apparent security?

I do not want to participate in the discussion, in which Dave or you, do not present scientific papers. All of which shows that this method is recommended and widely tested.

#122 (permalink)

greet rc
 
More threats eh Dave..
Bob:

(1): Keep discussions civil and on track.

(2): Respect the use of humor when used. I use it often. I often use smilies... :flame:

(3): Recognize that we are a community of friends, and act towards others as if they were personal friends that you regularly meet at the market.

(4): Recognize that people, including myself, are here because they choose to be here. Don't make demands... I only answer questions "on demand" from people that are paying me. I answer questions here when they are posed in a friendly way by people I wish to enage with as friends, when I have time, and as the mood strikes. If I don't answer a question it's probably because I don't feel that my time is being used wisely, or I am just too busy, or I am bored with the conversation (IE: it's become a discussion of the discussion...)


This is another of the gentle chidings that I have given. I have absolutely no intent to let this forum devolve into anything less than the best that we can expect from people. That's as strong a suggestion as I can make to follow and respect our ethos.

Further off-track meta-discussions (discussions of the discussion) made by anyone, or discussions of people and their personalities, value, or attrributes will be deleted and the person making the post will be given a 14 day sit out to contemplate their desire to participate in the community here. I trust that this is clear guidance as to our expectations?


Back to any germane technical discussion now.


Best,

Dave


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What is the sense of apparent security?

I do not want to participate in the discussion, in which Dave or you, do not present scientific papers. All of which shows that this method is recommended and widely tested.

#122 (permalink)

greet rc

What do you want scientific papers on, common sense?

You have a whole other agenda then what has been presented by Dave. You bladder about stuff that isn´t signification to the tests he is talking about. And when you can answer a simple question you withdraw from the discussion because their is no scientific papers on the subject.

I don´t agree with everything Dave says, but here he has a point. It´s better to have a hunch about how the body reacts to hypoxia than know nothing at all. All knowledge is good and it might save your life one day.

Scientific papers doesn´t show anything. Just look att all papers that has been written about decompression. All are theories, would you use them as solid prof just because its a scientific paper?
 
#171 (permalink)

greet rc

Ok, what of this.

They are talking about rapid compression from N2+O2 180mm hg ... they mean 0.23 ish PPO2 or what?

Then that part of article talks about PILER-light, bronchodilation and rehabilitation it's just an abstract from a paper about something else, I think.

I don't see relevance to this subject
 
They are talking about rapid compression from N2+O2 180mm hg ... they mean 0.23 ish PPO2 or what?

Then that part of article talks about PILER-light, bronchodilation and rehabilitation it's just an abstract from a paper about something else, I think.

I don't see relevance to this subject

I was on this course seven years ago, included a wide physiological data information. Oxygen partial pressures achieved in this experiment came to 2.2 at.
Conclusions were much more interesting.

That light is the result of the Soviet space program, it was shown that the reduction of hypoxia at the cellular levelcan either reduce the rate of compression or use the lamp.
Professor Gulyar conducted research, results presented at the Scientific Conference of the Polish Society of Medicine and Hyperbaric Technology.
This is a serious way of presenting research.

greet rc
 
^^^ to the above...

I'm sure this is interesting, but it is off topic for this thread.

If you feel that the studies are worth the interest of the community here, please start a new thread for it specifically. All subjects are welcome.


Thanks,

Dave


,
 
Dave,

I have stayed out of this discussion, largely because I suspect the debate is unresolvable. On the one hand your points are largely well made: hypoxia exposures do take place regularly as a training intervention, mainly in aviation. The incidence of harm is close to zero. On the other hand, Bob's question about the utility of the exposure in preparing a diver to recognise hypoxia in the dynamic underwater environment is also valid. On that basis he questions the benefit.

I would make the following points.

In using the aviation scenario to justify your advocacy for an hypoxic experience in divers you are choosing to downplay one issue that deserves closer consideration. In most of the aviation training scenarios in which hypoxic exposure takes place there are strict protocols around health screening of the candidates and supervision of the scenario itself. The extent to which this contributes to the almost invariably harmless outcomes is simply unknown, but it is at least plausible that that it does (contribute). The widespread use of hypoxia training in divers is unlikely to be associated with the same standards of screening and supervision of the drill itself. Whether or not this would unmask a safety problem is unknown in my view. I still suspect that the truth is it would remain a relatively safe exercise.

However, the truth in relation to this issue is likely to be much less important than the perception when something eventually does go wrong in relation to an hypoxia exercise. The diving group conducting the exercise will be subjected to an uncomfortable degree of scrutiny which will find some stark differences between their operation and the typical aviation industry setting. There will be no shortage of "experts" prepared to testify (probably incorrectly) that the exercise should never have taken place because it was too hazardous. If I was a diving operation owner I would be checking that my professional liability insurance covers me for this sort of thing because I can guarantee you that some insurance companies would use the excuse that this is not standard diver training and that there is no way the cover extends to intentionally rendering students hypoxic etc etc.

Do these various "risks" mean that we should not do it? I don't know the answer to that to be honest. This is where Bob's point about utility becomes relevant. "Risk" vs benefit? I don't know the answer, but people getting into it (especially at a professional / dive shop level) should think about it carefully.

Finally, I would suggest that when you are personally debating other members of the forum then you set your moderator's role to one side and leave things like "gentle chidings" out of the discussion. If a debate in which you are participating needs moderating, then get one of the other moderators to do it. There are risks in moderating your own debates, including sounding like a condescending school master. I'm sure you would want to avoid that.

Simon M
 
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If I was a diving operation owner I would be checking that my professional liability insurance covers me for this sort of thing because I can guarantee you that some insurance companies would use the excuse that this is not standard diver training and that there is no way the cover extends to intentionally rendering students hypoxic etc etc.
Continental Europe has a different legal system than the UK or the U.S..
Read the 122nd entry

rc greet
 
Simon's post wins the thread. Dave, I know and truly appreciate that one of the reasons that you started CCRX is to have an alternative to the other tech-oriented boards, where the mods can be rather heavy-handed and biased. IMO, it's somewhat hypocritical to "swing your dick around" in a discussion in which you are participating, no matter how gentle the swings. If need be, please have Clare or another disinterested mod do the mod work. I really do believe that anarchista and others have valid points, as unintelligible as they may be.
 
I really do believe that anarchista and others have valid points, as unintelligible as they may be.



I do as well, which is why I suggested that they start a new thread! That's a proper request from the forum, and is done for a reason that might be obscure but that will make sense if you think about it. The content here is an archive, and in ten/twenty/thirty years the content will still be available. Searching for topics of interests "later on" is generally done by thread title, so it's important to keep topics on-title, and to start new threads whenever the subject strays. This is a simple library-resource organization request, not a "conspiracy". If people cannot search for information, they cannot find it. The way we search i by threads, Threads NEED to stay on track. It's that simple. I've posted this request earlier, and re-post it now. Our friend anarchista et-al can start as many threads as they like, on whatever DIVING subject that they choose. Threads are free... start one!

With that said, the basic ethos of the site is that we do not use profanity, we do not discuss people or their value, do not make fun of or detract from other posters, and treat everyone as if we meet them daily in the market. I will moderate for this sort of thing in any thread, for anyone being treated disrespectfully, and that includes myself. If anyone feels that they are being treated disrespectfully by anoyone else, then please let myself or another moderator know and we will start by sending the poster a gentle note, then we will progress to a more public chiding, and finally we will (if needed) give people a time out. This is how we keep this a friendly place for everyone. So far we have never needed to resort to anything other than a public "That's not very nice". Saying things such as "so another threat, eh?" is, well.... not very nice. We do not have a large staff of moderators, and as a result I often need to wear two hats (unless you want me to only moderate and not provide any content), but I always try to tread softly and will always be fair. If anyone ever thinks being chided is unfair, then send a note to Clare. I would note that we have NEVER needed to remove a post, have only I think twice edited a post, aand have never needed to ever remove a member. This is the least moderated diving site know. That's due to a basiclaly good group of guys, and an ethos tha we make clear and then try to gently persuade people into embracing.


Now: Meta-discussions in a thread of "how the thread is being managed" is off topic, and is a distraction to the actual content. Some other forums, which you migbht read, end up being almost nothing BUT meta-discussions, discussions of the individuals participating, and aggressive behaviour that inhibits FRIENDY and PROFESSIONAL debate among PEERS. I will not permit that here. Clear and fair?


So, this ends the meta-discussion, and I trust that the reasons for this policy is not only clear, but also is one that we all understand and support. I expect nothing but the BEST in both attitude and content from our friends here. Discuss anything, but let's stick to the basic framework that I have laid out here. I probably ought to write it up as a sticky, but "generally" people seem to understand it intuitively, which in itself is commendable. Well done all.


Now then:, if anyone wishes to dicuss the subject articulated by title of the thread, let's feel free. If we want to discuss arcane Russian scientific papers, let's start a thread and see where it goes, and I am sure will all learn something. If we want to have a meta-discussion "on the discussion" it will be deleted without comment or any additional coaching on the purpose of the forum, which is rebreather diving, and not how the internet social structure evolves. I am absolutely certain that there are other forums dedicated to that exact subject.


I spend about an hour a day reading every post here, participating as my expertise permits, stay silent when I have no expertise in an area, and generally sit on my hands and enjoy the show. It's a lot of work, and I trust that it's appreciated. It's not always going to satisfy everyone, but we do try.


The rules above are not going to be compromised, but ought not to do anything other than keep the table clear for a nice enjoyable discussion.



Fair?


Dave


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Simon's post wins the thread. Dave, I know and truly appreciate that one of the reasons that you started CCRX is to have an alternative to the other tech-oriented boards, where the mods can be rather heavy-handed and biased. IMO, it's somewhat hypocritical to "swing your dick around" in a discussion in which you are participating, no matter how gentle the swings. If need be, please have Clare or another disinterested mod do the mod work. I really do believe that anarchista and others have valid points, as unintelligible as they may be.

We could go talk about it on the BSAC forum? :lol:
 
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