Hyperinflation of lungs

some patients that come here that are newbies often complain of sharp pains in the lung area, this is sometimes confused with rib pain, it is akin to a cracked rib (well not that painful but it feels darn similar, sharp knife like pains), it usually goes away after a few weeks of becoming accustomed to cpap

My guess would be that may be from friction of the pleura membrane covering the lungs. I used to get that sensation sometimes when I simply took a deep breath. It was quite painful, but only temporary and I haven't felt it in years - never as a result of CPAP use.

BarryKaraoke wrote:

split_city wrote:I would have to disagree with this. CPAP does increase lung volume quite effectively.

Of course it increases lung volume and splints open the airway...it wouldn't be effective treatment if it didn't do this.

The point, is that a CPAP machine is not going to somehow "over inflate" your lungs to the point of damage/rupture, as the OP fears.

My apologies. Your original post was confusing to me (and perhaps others) as it hinted that CPAP has no effect on lung volume.

BarryKaraoke wrote:A CPAP machine does not (and will not) "inflate" your lungs...it will hardly inflate a beach ball

But it seems you have cleared up what you meant.

BarryKaraoke wrote:
SnoreDog & Split_City: Are you both then answering the original poster with a YES? That there IS a risk of "Lung Hyperinflation" with CPAP? Or merely arguing over semantics?

My answer would be NO to the OP. I would hardly call it sematics as what you originally said is completely different to what you actually meant. I wanted to clear it up for other posters.

Snoredog wrote:So is that manipulation by the mechanical device somehow overriding that stretch receptor function? What part of the respiratory drive tells our brain the lungs have filled to capacity?

This is all very interesting. The Hering-Breuer reflex is the reflex which prevents over-inflation of the lungs. CPAP would likely have very little effect on this reflex because you aren't breathing at total lung capacity on CPAP.

The chest pain experienced by several OSA patients may not entirely be due to the strecthing of the rib cage. Increasing lung volume, via CPAP, also changes the operating length of the respiratory muscles. All these muscles tend to work at their optimum when they are at a certain length. By changing the length of the respiratory muscles i.e diaphragm, intercostal, they may now be operating at a less efficient operating length. This means they have to work harder to produce the same output.

Anonymous wrote:My apologies. Your original post was confusing to me (and perhaps others) as it hinted that CPAP has no effect on lung volume.

And my apologies as well. Often, no matter how hard you try, you can't seem to get your point across in cyber-land. And sometimes you end up coming across exactly the opposite of your intent!!