Visit with NP - mouth air leak issue & pressure settings

[sleepychar]

I started CPAP (APAP actually) on July 15th so it has been approx 6 weeks since starting. The biggest problem I seem to be having is waking up alot at night with air rushing out of my mouth from my throat and very dry mouth. I am using a chin strap and I am just about positive my mouth isn't just dropping open and I am not inhaling though my mouth and the air is coming from my throat. Some nights are worse than others. Seems to be happening when machine has increased the pressure. I have tried scuncii over my mouth and I also tried taping my mouth. Neither one was a solution. I am considering either a hybrid or full face mask at some point. Pressure setting had been 4-16 starting out and I increased the lower number to 6 after a time. Today I met with the nurse practitioner in my sleep doc's office. I had left a message for the doctor letting him know I was having problems with waking up, mouth air leaks, dry mouth. Today the nurse practitioner told me the doctor was changing the pressure setting to be 4-12 instead of 4-16. After I explained I was finding it easier to inhale with the lower setting at 6, nurse practitioner decided the new pressure range would be 6-12 instead of 4-12. I have moderate COPD. My own intuitive theory from my experience so far has been that as the pressure increases, more air is trying to be sent to my lungs but since my lung capacity is somewhat diminished, all that air can't go down into my lungs and so is going out my mouth. Tidal volumes have been observed, when my SleepyHead reports were reviewed here, to be on the low side but that didn't come up in today's discussion. But I did bring up that I thought my lungs couldn't handle the amount of air pushed down during high pressure episodes. The nurse practitioner told me that it is not a greater volume of air being pushed to my lungs, just that the air pressure was increased to handle apneic events. Is she correct? To me it seems that if the air is going in at a higher pressure, there would be a greater volume of air... I would like to be able to find the lowest high end of the pressure range that would prevent apneic events and maybe then the mouth air leaks would be less. However, the mouth air leaks have occurred when the pressure is like 10.78, 11.2 when I have looked at the machine LED display at the time these were occurring, and going back over my SleepyHead reports, the max pressure ever since I have started was 12.08 and that was only one time, so I'm thinking that lowering the pressure to 12 is not really going to help - if my theory about volume of air is correct, which it may not be. I was encouraged that I think at least the doctor must have reviewed my sleep reports because he did select the top max number so far in my reports for the top range number. I will be seeing the doctor himself in about a month from now after we have a chance to see how the new settings are working out. Honestly, I don't see how this change is going to make any difference. The nurse practitioner wants me to try a full face mask or a hybrid mask. I agreed to do that as soon as my insurance will cover it but I expect that is still a month and a half in the future - which is really ok with me since I want to keep trying with the pillow mask. I'll see what the DME has to say but I know my insurance will only cover a new mask every 90 days and I am past the 30 day trial period for the P10 pillow mask. So my question today is whether when the air pressure is increased, does that increase the volume of air being pushed to my lungs?

[Julie]

You're assuming all the air pumped in goes to your lungs... it does, but only in such minute trickles by the time it gets there as not to matter one way or the other... cpap's only job is to help open your airway more and then weakens quickly. Yes you're breathing, but not at a rate to have it go to your lungs with any meaningful pressure... and only as much air ends up in your lungs as would be processed by your body's need for air as with any breathe you take with or without Cpap... it dissipates before plowing into the lungs at the rate you imagine, but it's not strong enough to reach your lungs with any (stronger) force than any other breath by the time it gets that far down. The machine isn't designed to keep pushing it down there, only to the blockage higher up. If your mouth remains open, air will continue to leak out, and a higher pressure going in will enhance it, but that doesn't mean more is going to your lungs.

[palerider]

My own intuitive theory from my experience so far has been that as the pressure increases, more air is trying to be sent to my lungs but since my lung capacity is somewhat diminished, all that air can't go down into my lungs and so is going out my mouth. ... So my question today is whether when the air pressure is increased, does that increase the volume of air being pushed to my lungs?

no, the machine you have simply applies a steady pressure to help keep your airway open, any "extra pressure" just goes out the mask vent.

machines that actually have the capability of pushing air into your lungs go up to 25 to 30cm/h2o. your extra 2cm from 4 to 6 is nothing as far as air being 'pushed into your lungs...

sorry, look elsewhere.

[sleepychar]

Thanks for your responses. I wasn't concerned about the change from 4 to 6 minimum pressure. I was thinking about the upper end possibly being too high for my lungs to handle. But I see my theory was incorrect.

[palerider]

Thanks for your responses. I wasn't concerned about the change from 4 to 6 minimum pressure. I was thinking about the upper end possibly being too high for my lungs to handle. But I see my theory was incorrect.

resmed makes a specialized COPD machine, and it offers pressures up to 30cm, as well as customizable changes in pressure to make it easier to breath.

[ChicagoGranny]

You're assuming all the air pumped in goes to your lungs... it does, but only in such minute trickles by the time it gets there as not to matter one way or the other... cpap's only job is to help open your airway more and then weakens quickly. Yes you're breathing, but not at a rate to have it go to your lungs with any meaningful pressure... and only as much air ends up in your lungs as would be processed by your body's need for air as with any breathe you take with or without Cpap... it dissipates before plowing into the lungs at the rate you imagine, but it's not strong enough to reach your lungs with any (stronger) force than any other breath by the time it gets that far down. The machine isn't designed to keep pushing it down there, only to the blockage higher up. If your mouth remains open, air will continue to leak out, and a higher pressure going in will enhance it, but that doesn't mean more is going to your lungs.

Good grief.

[sleepychar]

I'll be discussing everything with my doctor when I meet with him next month. I wasn't quite believing the nurse practitioner today but it sounds like she was correct. I really want to adjust to the pillow mask and not have to go to different type of mask but that may be what I have to do. I'll see what happens over the next 6 weeks in terms of adjusting to the P10 mask because I think that's how long I probably have to wait for my insurance to pay for a new mask anyway. But I would probably try a hybrid or full face mask before looking at a different type of machine. But it's good to know that's another option. It's mainly the air leak out of my mouth and severe dry mouth that results and it wakes me up at night that is the problem right now and I was hoping adjusting pressure settings on the machine would help with that. Or maybe just tincture of time will help. I notice other people in this group saying that they had this same problem and it went away in time. I was hoping that lowering the pressure at the top end enough, since that is when the problem seems to be occurring, would prevent the air leak and I was basing that thinking on an incorrect theory of how the machine works, but I see that I was off on a completely wrong track.

[Pugsy]

I was hoping that lowering the pressure at the top end enough,

That air entering the mouth from the airway....that can happen with pressures as low as 5 cm.
People complain of it all the time even at lower pressures BUT it hurts nothing to try limiting the maximum to see if it helps or not.

Here's the thing though...if your maximum was 16 and the machine never went to 12...lowering the maximum to 12 isn't going to change anything. The machine never went there anyway so making where it could go to isn't going to change where it does go to if it never went there in the first place.
So unless you spent a lot of time above 12...limiting the max to 12 is unlikely to change much.

[palerider]

I'll be discussing everything with my doctor when I meet with him next month. I wasn't quite believing the nurse practitioner today but it sounds like she was correct. I really want to adjust to the pillow mask and not have to go to different type of mask but that may be what I have to do. I'll see what happens over the next 6 weeks in terms of adjusting to the P10 mask because I think that's how long I probably have to wait for my insurance to pay for a new mask anyway. But I would probably try a hybrid or full face mask before looking at a different type of machine. But it's good to know that's another option. It's mainly the air leak out of my mouth and severe dry mouth that results and it wakes me up at night that is the problem right now and I was hoping adjusting pressure settings on the machine would help with that. Or maybe just tincture of time will help. I notice other people in this group saying that they had this same problem and it went away in time. I was hoping that lowering the pressure at the top end enough, since that is when the problem seems to be occurring, would prevent the air leak and I was basing that thinking on an incorrect theory of how the machine works, but I see that I was off on a completely wrong track.

basically, disregarding granny's snide comments, your cpap doesn't breath for you, it just holds your airway open so YOU can breath... the only air flow in and out of your lungs is what you create, just like during the day when you're awake.

now, there ARE advanced cpaps that will breath for people whose brain doesn't tell the lungs to inhale, but yours isn't one of those.

[sleepychar]

Got it! Thanks -

[sleepychar]

"Here's the thing though...if your maximum was 16 and the machine never went to 12...lowering the maximum to 12 isn't going to change anything. The machine never went there anyway so making where it could go to isn't going to change where it does go to if it never went there in the first place.
So unless you spent a lot of time above 12...limiting the max to 12 is unlikely to change much."

That's what I thought - that it won't make any difference. But my thinking about getting that pressure low enough to stop the leaks was based on my incorrect understanding of how CPAP works. So now I know better... Thanks to everybody for clearing this up for me... And it restores my faith a little bit in the nurse practitioner who I wasn't really believing today. But why the doctor even bothered to make that change, how he thought it could help, I don't know... I'll just keep on and see what happens over the next bit of time...

[raisedfist]

just an fyi, take a moment to format your posts...no one enjoys reading a wall of text

[Pugsy]

But why the doctor even bothered to make that change, how he thought it could help, I don't know

Sometimes docs make little changes because they think that the patient thinks it might help and if it doesn't hurt to make the change or try it...why not make the change.

Here's the other deal...even if you switch to a full face mask of some sort (either the hybrid or regular) there's no guarantee that it will fix the dry mouth issue.
We have many forum members using a full face mask at maximum humidity still complaining of dry mouth and using all sorts of products designed to help with dry mouth. I know that probably isn't what you wanted to hear but it's the truth.

About all we can guarantee with a full face mask is that the therapy pressure isn't exiting your mouth so your therapy won't be compromised and at this point without ever seeing your data...we don't know just how much (if any) therapy pressure is exiting your mouth.

[sleepychar]

I think I am not losing that much therapeutic pressure. Usually my leak levels are quite low overall although every once in awhile there are some large leaks but not that often. It is mainly the waking up and dry mouth that bothers me. If there isn't any great hope of losing the dry mouth, it may not be worth it to switch to full face mask. On the other hand, if I could sleep through and not wake up so much, that would be an improvement. My AHI is not that high, occasionally it is 3 or 4 but mostly it is 2. something or 1. something and mostly clear airway events with a couple of OA and hypopneas thrown in. I may post SleepyHead charts again but they were reviewed here not that long ago and didn't look that bad.

[Pugsy]

I may post SleepyHead charts again but they were reviewed here not that long ago and didn't look that bad.

I don't remember seeing them but then I have probably slept since then. and while my memory is usually fairly decent...it isn't without failing at times.

I will go back and look to see those graphs to see if something stands out.

I don't know if using a full face mask will help with the dry mouth or not...it might and it might not.
And if the dry mouth is the only reason you wake up then it's probably worth at least trying at some time in the future just to make sure you have tried everything you can try.

I know how frustrating it is to wake up often when we don't want to. It's something I deal with almost every night for reasons unrelated to cpap. It doesn't matter what the reason it...multiple wake ups just suck. Anything that wakes us up often is unwanted...no matter how big or small the reason might be or whether it harms therapy itself or not.