CPAPtalk.com

geager wrote:

tonycog wrote:If your air-way is blocked (the definition of obstructive sleep apnea), it does not matter whether you breath through your mouth or nose. The air will not get to your lungs.

If my husband happens to fall asleep in his recliner,he can be breathing quietly and peacefully through his nose with his mouth closed, and then all of a sudden he's not breathing and gasping for air. Of course I wake him immediately and he puts on his mask.

DoriC wrote:

geager wrote:

tonycog wrote:If your air-way is blocked (the definition of obstructive sleep apnea), it does not matter whether you breath through your mouth or nose. The air will not get to your lungs.

If my husband happens to fall asleep in his recliner,he can be breathing quietly and peacefully through his nose with his mouth closed, and then all of a sudden he's not breathing and gasping for air. Of course I wake him immediately and he puts on his mask.

This is one of the things that concerns me -- I fall asleep in my recliner almost every day. I usually only sleep for about 10-20 minutes, but it still concerns me. The last time I felt that sleepy and tried to lay in the bedroom with my machine, I couldn't fall asleep. Go figure.

Raj wrote:Muffy, I'm not sure the Buteyko people would find your graph convincing. The problem is that you adjusted it for a normal pH, which turns the data you presented into a bit of circular reasoning.

OK, no problem. Using Henderson-Hasselbach, I have converted the compensated blood gas back into it's uncompensated state, which results in a pH of 7.52. Using the same pCO2 of 30 mmHg and pO2 of 80 mmHg, you can once again see that the point of intersection of pO2 80 mmHg (and that's like a fairly low normal) on the oxygen dissociation curve is barely indiscernible form the "normal" state:



Muffy

Raj wrote:I doubt the Buteyko people would suggest that extreme and consistent hyperventilation is the norm. I think what they're attempting to address is far more subtle ...

And if that's the case, then trying to apply Bohr is inappropriate.

Muffy

Muffy wrote:

Raj wrote:Here is what is actually known (as apart from theorized): if blood contains too little CO2, blood pH fails to drop far enough to separate O2 in blood from hemoglobin, resulting in some degree of cellular oxygen starvation depending on the severity of CO2 shortage. This principle was discovered in 1904 by the Danish physiologist Christian Bohr.

In chronic hyperventilation (chronic respiratory alkalosis), the kidneys excrete -HCO3 in order to correct pH. Compensation starts at about 6 hours and completes in 2 to 4 days, dependent upon a number of factors, but pH normalizes.

With this compensation (and for that matter, even without it), the effect on the oxyhemoglobin dissociation curve is negligible:



In this example, pCO2 of 30 mmHg is utilized, which would represent substantial hyperventilation, and as you can see, at pO2 80 mmHg the difference is indiscernible.

Muffy

Gotta say that what Muffy is saying makes sense. I am not neccesesrily a fan of Muffy's conversational style but I do know when what Muffy has said is fundamental and meaningful.

As an aside, Buteyko is great when you are young & fit. But to put it very bluntly (from my experience), the techique can bite your bum when you get a lot older. Cpap may prove to be the salvation of a lot of buteyko believers as their musculature ages and other complications (aging & dietary related) intrude.

I like to wish everyone who tries any practiced discipline well, but, sometimes the apparent cure can turn into tomorrow's problem. Cpap is very fundamental, very basic, very pure - with the right machine you simply breathe. Restated: The right machine can make you breathe when you need to which may not always be in line with one's philsophical need to breathe at a particular rate or time. The worst case scenario for when philosophy fails and when practicality wins is the awful story of the world's (in)famous 'breathairians'.

(Note: Australia has a strong sensitivity to alternative practices & breathairianism has featured prominently here in the past - see http://en.wikipedia.org/wiki/Inedia -
this is not in any way intended to denigrate buteyko breathing - but, there are parallels )

DSM

Last fall, prior to starting cpap I followed a link to some videos on u-tube about the buteyko technique and found the control point measurement a great way to monitor asthma severity when not at home where my peak flow meter lives. I also found the basic exercise can help reduce asthma symptoms.

I can't understand how someone would think buteyko exercise and taping ones mouth at night would prevent OSA. I will continue to use the basic buteyko exercise to reduce asthma symptoms and my cpap to prevent/reduce RERAs.

Muffy wrote:

Raj wrote:I doubt the Buteyko people would suggest that extreme and consistent hyperventilation is the norm. I think what they're attempting to address is far more subtle ...

And if that's the case, then trying to apply Bohr is inappropriate.

So if we use our curve calculator to create a scenario of subtlety (slight increase in breathing to give pH 7.43 pCO2 37 with a more normal pO2 of 90)



the curves at intersect are superimposed, so Bohr Effect becomes non-existent.

Muffy

Muffy wrote:...the curves at intersect are superimposed, so Bohr Effect becomes non-existent.

OK, let's wait just a minute there, yeast-breath!

Are you saying that hypocapnia is harmless?

Are you ignoring the tons of data that clearly demonstrate the deleterious effects of hypocapnia?

For instance, our friends in Wisconsin (AKA "The Dempsey Group") noted in Controlled versus Assisted Mechanical Ventilation Effects on Respiratory Motor Output in Sleeping Humans that

Present findings extend previous results (discussed previously in this article) by showing in the sleeping human (1) that the increased frequency of CMV need only be as little as one breath per minute above spontaneous eupnea to eliminate respiratory motor output

Or the classic article on Hypocapnia by Laffey who concluded

On the contrary, increasing evidence suggests that hypocapnia appears to induce substantial adverse physiological and medical effects.

Well?

What s'matter?

Cat got your...

...your...

...whatever?

NotMuffy

NotMuffy wrote:Or the classic article on Hypocapnia by Laffey who concluded

On the contrary, increasing evidence suggests that hypocapnia appears to induce substantial adverse physiological and medical effects.

Laffey? What'd he do besides overventilate a bunch of rabbits?

Poor Bunnies!

Injurious mechanical ventilation strategies, associated with adverse outcome, commonly result in systemic hypocapnia. In this paradigm, worsened outcome is thought to be due to the combination of excessive lung stretch and shear forces resulting from repetitive recruitment and de-recruitment of atelectatic lung segments. This causes barotrauma or volutrauma, increased pulmonary production of cytokines, or pulmonary to systemic translocation of bacteria or endotoxin. This is called ventilator-associated lung injury (VALI). In all such instances, hypocapnia has been thought to fulfill a passive role.

Muffy

Muffy, would you mind providing a link to that calculator? I want to vary the CO2 values and see what happens.

Thanks,
Raj

OK, by now you may have noticed that of the variables that change the behavior of the oxyhemoglobin dissociation curve, temperature can have the greatest effect. For example, this guy:



has shifted his curve way the heck out there:



such that his P50 is an anemic (so to speak) 13.82 mmHg.

Muffy

Raj wrote: I doubt the Buteyko people would suggest that extreme and consistent hyperventilation is the norm. I think what they're attempting to address is far more subtle and, to add an extra confound, inconsistent.

I have reviewed with a very critical eye what the "Buteyko people" are suggesting, paying particular attention to their discussions about minute ventilation and what is "normal", referring to a popular purveyor of this therapy:

http://www.normalbreathing.com/index-table2-healthy.php

including detailed analysis of their key references

http://jap.physiology.org/cgi/content/full/90/3/889
http://jap.physiology.org/cgi/content/full/104/1/57

and after careful consideration, I have decided that the "Buteyko people" are a bunch of FnAHs.

Muffy

Hey Muffy, I can't pretend to understand what's going on but I have a query. (don't worry, it's not contagious!)

I tend to sleep better, or at least, fall asleep better on the nights when I've had a long, hot bath. Could internal temp increase have any impact on Complex sleep apnea?

Deon

Muffy wrote:... after careful consideration, I have decided that the "Buteyko people" are a bunch of FnAHs.

Thank you. That's exactly what I wanted to hear.

Cheers.