Expiratory Flow Limitations

[imposterdroids]

I've done the full face mask too but still get a graph similar to the one Rubicon posted - so it's definitely not mouth breathing.

But if you have palatal prolapse, it has to be mouth exhalation, otherwise there'd be no exhalation at all.

Frankly, I find that "classic" PP waveform a little confusing. Why, when PP supposedly starts, does tidal volume drop? PP is a one-way valve so inhalation shouldn't be affected. Or has baseline -0- dropped because of an LL?

Sorry for the long delay - I'm not getting notifications for new posts. Going to poke around and see if I can fix it.

Disclaimer: I haven't slept much in the last 3 days, so this post could be a load of nonsense.

I'm a little confused though. Does palatal prolapse have to mean complete closure of the nasopharynx on exhale? That's not my experience. A lot of times It's merely a flow limitation that makes you exhale slowly over a longer period of time - because the airway is severely narrowed from the palate ballooning. Isn't that what the flow graph suggests?

As for the tidal volume dropping, I thought this was explained in that article, "Palatal Prolapse as a Signature of Expiratory Flow Limitation...". From what I read it was caused by prolonged over-inflation of the lungs - basically you can't exhale fully so you're left inhaling and exhaling with remaining (upper?) volume of the lungs.



BTW SleepyCPAP, Got my alaxostent last week. I've barely slept, but making improvements as I adjust it's positioning. Got any tips for the correct position? Do you look in a mirror and see if it protrudes below the palatal arch at the back of your throat?

[Rubicon]

As for the tidal volume dropping, I thought this was explained in that article, "Palatal Prolapse as a Signature of Expiratory Flow Limitation...". From what I read it was caused by prolonged over-inflation of the lungs - basically you can't exhale fully so you're left inhaling and exhaling with remaining (upper?) volume of the lungs.

The tidal volume does not, and cannot drop because what goes in has to (eventually) come out.

Go to figure 6. They're only looking at short bursts which are apparently terminated by arousal. The first breath is missing ~200 ml which is stuck in the lungs because of PP. Consequently EELV is higher (and creeps up a little) for the ensuing breaths. If they were to carry that out to post-arousal, the trapped breath volume would be exhaled and EELV would return to baseline.

This differs from Oscar downloads with guys using nasal pillows because

In some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth.

[jimbud]

In some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth.

That's me (at least I think?).

I wear a cervical collar to hold the chin up, and a terry cloth elastic band across my mouth that restricts and slows exhalation when that happens. (Plus adjustable elastic band over terry cloth one.)

Which also allows me to hold therapy pressure up. So far I have awakened every morning...so far?

JPB

[SleepyCPAP]

BTW SleepyCPAP, Got my alaxostent last week. I've barely slept, but making improvements as I adjust it's positioning. Got any tips for the correct position? Do you look in a mirror and see if it protrudes below the palatal arch at the back of your throat?

For many weeks I’d check in a mirror. I found that I need to see at least a little (1/4 inch) hanging lower than my palate _after_ I’ve swallowed a few times. The stent sometimes squnched up, almost as if the swallow motion pushes it into a bunch. It still works up there, but not as well. So I start in the lower position.

Once I figured out the right placement, I don’t look anymore. I just see how much is coming out my nose and make sure it is just as long as usual.

-SleepyCPAP

[imposterdroids]

The tidal volume does not, and cannot drop because what goes in has to (eventually) come out.

Go to figure 6. They're only looking at short bursts which are apparently terminated by arousal. The first breath is missing ~200 ml which is stuck in the lungs because of PP. Consequently EELV is higher (and creeps up a little) for the ensuing breaths. If they were to carry that out to post-arousal, the trapped breath volume would be exhaled and EELV would return to baseline.

This makes sense. Only thing I can say at this point is that I've probably missed or misunderstood what was meant by a drop in tidal volume, or the context in which it was used. Really not surprising though considering how little sleep I've had recently. I'll return to this when I'm rested and see if a light switch comes on.

For many weeks I’d check in a mirror. I found that I need to see at least a little (1/4 inch) hanging lower than my palate _after_ I’ve swallowed a few times. The stent sometimes squnched up, almost as if the swallow motion pushes it into a bunch. It still works up there, but not as well. So I start in the lower position.

Once I figured out the right placement, I don’t look anymore. I just see how much is coming out my nose and make sure it is just as long as usual.

-SleepyCPAP

Appreciate the info! Also, I saw your post in another thread about the stent having two possible locations, the 2nd being down at the tongue base, which was news to me. When I used the nastent device, it needed to be around 155mm to improve my sleep, so at 6" the alaxostent will have to be almost fully inserted. I'm hoping though, that the "swallow motion" doesn't cause it to extend into the epiglottis. (I've experienced it squenching up when its above the palate, but also extending when its below it. Just trying to find the correct location and a way to get it in the same place each night. Probably going with the mirror approach for a bit. Thanks!)