Talk:Apnea

message: There is a potentially fatal "apneist" technique, believed by some of its practioners to amount to a safe hyperoxygenation of the blood.  In fact what allows them to hold their breaths longer is that they have reduced their blood CO2 to abnormally low levels, delaying the time when the buildup of CO2 forces breathing, by a time roughly equal to the time in which produces the amount of the initial CO2 deficit.  The danger, as i understand it, is that a sufficient CO2 deficit can hold off the impulse to breathe so long that loss of consciousness occurs first, producing a high likelihood of drowning when the technique is for underwater activities.
IMO, the discussion of ==Apneic oxygenation== is sufficiently hard for lay readers that it might be seen as an endorsement of the technique i am refering to.  
And in any case, should the danger of the CO2 deficit technique i refer to perhaps be part of this article? --Jerzy 02:17, 2004 Feb 21 (UTC)
---
Earlier in the article it was mentioned that some people have learned to increase their period of voluntary apnea up to 7 minutes, and it notes that trained free divers hold their breath for a long time. This seems to have introduced the subject of prolonged apnea while diving. However, there is no discussion of how these effects are achieved. Since the article holds out the hope that an increase can be achieved, it seems relevant to point out an obvious (but wrong) path that should not be followed. I have observed a diving instructor warning students on this. If the warning is not clear enough, perhaps it can be improved.
The paragraph on the voluntary hyperventilation technique confusingly contradicts itself.   —Preceding unsigned comment added by Justin Stafford (talk • contribs) 18:04, 4 June 2010 (UTC)
thread_title: Untitled

message: Please do not change "apnea" to "apnoea". This article was obviously created with the American spelling, or at some time changed to the American spelling. All occasions show the American spelling, it is not on to suddenly change some words to the British spelling. We must respect this. Have changed the article to wwhat it was before. Dieter Simon 21:30, 16 October 2006 (UTC)
thread_title:  Changing the keyword to apnoea 

message: not much difference, I would say... -- Robodoc.at 22:15, 23 October 2006 (UTC)
thread_title:  What about [[Respiratory arrest]] ? 

message: "If a person loses consciousness underwater, especially in fresh water, there is a considerable danger that they will die by drowning."
This is just a personal curiosity - but why is this the case? My only guess is that it has to do with the buoyancy of humans in salt water.
:It has to do with osmotic effects. When permeable tissues, e.g. red cells and lungs, are exposed to a non-isotonic solution, water will flow from the region of higher water concentration (fresher solution) to the lower. Consider what happens if you place some blood in fresh water versus in salt water. In salt water the red cells in the blood will lose water and shrivel. In fresh water the red cells will swell until they burst. It is simply much easier to receive irreversible damage to your body in fresh water. --AJim (talk) 18:13, 18 March 2009 (UTC)
replies: text: I am adding a link to the drowning article discussion of secondary drowning. They make the point that hypoxia is usually what kills you, but I thing it is clear that fresh water will do more damage, and the point is that death is more likely to ensue in a fresh water drowning. --AJim (talk) 16:52, 24 March 2009 (UTC)

text: However, a detailed drowning discussion plays down the role of osmotic effects. The author agrees that salinity can matter, but not most of the time. --AJim (talk) 17:04, 24 March 2009 (UTC)
thread_title:  "Especially fresh water"? 

message: Please explain why a simple factual statement along the lines of 'the damage to alveoli caused by smoking reduces gas exchange efficiency' requires a 'citation required' tag. If no one can provide a concrete reason, this bogus tag is going. I didn't write any of the original article btw, just incensed at what seems blatent pro-smoking anti-factual trolling. I also happen to be a smoker, but I'm not an idiot. Blitterbug (talk) 09:58, 25 August 2009 (UTC)
thread_title:  'Citation Needed' Indeed! 

message: This section seems to contradict itself. If the effect is false, how can the effect be attributed to anything? 207.59.211.146 (talk) 13:08, 11 May 2011 (UTC)
thread_title:  Hyperventilation 

message: Sorry, but I don't see why the statement of the fact, that an untrained person usually cannot voluntarily hold her breath for more than one or two minutes needs a 'citation needed' tag. I would consider this public knowledge.
On the other hand, IMHO the fact, that a healthy adult breathing pure oxygen stores enough of it in her body that it would be sufficient for about an hour, is very interesting and I wonder where this claim comes from. So I allowed myself to add a 'citation needed' tag at this point. (Sorry, if I did something wrong, but usually I only read wikipedia and only edit once in a leap year.)
213.183.85.194 (talk) 13:52, 2 August 2011 (UTC)
replies: text:  I don't think "...that a healthy adult breathing pure oxygen stores enough of it in her body that it would be sufficient for about an hour" is common knowledge at all, and therefore that phrase does deserve the 'citation needed' flag which it currently has.  UnderEducatedGeezer (talk) 00:02, 10 November 2020 (UTC)
thread_title:  More or less Citation needed 

message: I just read the article to try to understand what is meant medically by apnea, and so far so good. However I read the section on hyperventilation which argues  that it is impossible to increase available oxygen by hyper ventilation, because blood in the body is always saturated. It immediately occurred to me that this argument is inadequate and needs further justification. I imagine (but don't know) that the largest part of oxygen contained within the body is present as gas within the lungs, and this acts as a reserve when not breathing. If hyperventilation increases the reserve of oxygen within the lungs, then it is not true that "hyperventilation of normal air cannot increase the amount of oxygen available." Normal breathing is quite shallow and does not fully empty or fill the lungs, so that inevitably they must contain stale air with lowerd oxygen content. If hyperventilation ensures that a dive starts with the maximum of fresh air in the lungs, then it will increase the oxygen available. 
I would also note that hyperventilation creats a 'buzz', and people having panic attacks are advised to re-breath into a bag to help calm themselves. The article would seem to imply that these effects have nothing to do with oxygen levels, but entirely co2. Is that really the case, because if not then these examples are evidence of real effects on the body from hyperventilation, presumably due to changed O2 levels, contrary to the assertion that oxygen levels are always unchanged by hyperventilation. Sandpiper (talk) 13:20, 27 September 2016 (UTC)
thread_title:  Hyperventilaion again 

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