question about mouth breathing

lvehko · Post by **lvehko** » Mon Jul 31, 2006 6:32 pm

The last week or so, I have gone to bed without taping my mouth (I'm using a nasal mask) and my results have been OK. However, I'm wondering if my machine would even know if I'm leaking through my mouth? Logically, it seems like if I were leaking from my mouth, I would see an increase in my AHI (or my leak rate?) -- is that true? I *think* I'm sleeping all night with my mouth closed, but I don't know for sure. What would I expect to see happen to my efficacy data if I were leaking from the mouth? -- Min

inacpapfog · Post by **inacpapfog** » Mon Jul 31, 2006 6:52 pm

Hopefully, minerva, you may have your mouthbreathing problem licked!
(no pun intented )
I would think that if you were leaking at the mouth, you would show a higher leak rate than before. I would also think that your pressure needs would increase in order to compensate for the air being diverted out of your mouth. This in turn could lead to higher AHI's.
But, since you report that these happenings are not the case for you, you most probably have reached your ultimate goal- NO MORE LEAKS!
(at least from the mouth anyway )

WNJ · Post by **WNJ** » Mon Jul 31, 2006 7:23 pm

Based on my own experience, I’d say that if you had mouth leaks you would wake up with a very dry mouth. If not, I’d say you’re now having no/minimal mouth leak problems.

If the leak were big enough, I figure it would adversely affect the way your CPAP detects “events.” But I can’t say for sure, since I switched to a FF mask before I got my REMstar Auto and software.

Wayne

rested gal · Post by **rested gal** » Mon Jul 31, 2006 8:20 pm

Whether we look at our overnight data in the window on top of the machine the next morning, or through software, a leak is a leak is a leak.

The machine can't differentiate between mouth leaks or mask leaks (or leak in the hose, or leak at a connection, etc.) All it can tell us is, "there was this much leak."

We have to be our own detectives if we want to track down the source of leaks over and above the normal exhaust venting.

As inacpapfog said, if the leak rate with mouth untaped is about the same as for the nights when you used tape, Minerva, you're most likely not leaking air out your mouth at all. Lucky you!

Stryker5777 · Post by **Stryker5777** » Mon Jul 31, 2006 8:57 pm

Yes, I agree a leak is a leak. However, I believe that there maybe universal tell tell signs of mouth breathing (leakage) that are obivous. Its hard to tell at this point tho but my theory is that a short straight (vertical) line leak should be apparent when there is no mouth breathing and variance on the mask's leak rate.

Since encore seems to automatically detect and account for mask leak rates that are constant (I remember reading why the leak rates are differnt between myencore and Encorepro's leak data). There also must be a upper limit for mask leaks that it doesn't report.

I think these are single short (vertical) line jumps in the leak rate base line, depending on the machine (bipap's seem to do this more than straight XPAPs, maybe because of the changes in pressure.) Or the second is a new plateau that jumps back down to the baseline. I think these are patterns that we might wanna look for on mouth breathing (leakage).

I would like to know if others see these same leaks and can not account for them anyother way. I can understand why we might think that there's no differnce between taping and not for leak rates. However, I argue that it might be possible that perhaps the tape isn't being effective if there's no change in leak rates?

Yours truly,

Stryker5777

lvehko · Post by **lvehko** » Mon Jul 31, 2006 10:07 pm

I think rested gal is right... but just to be obsessive, here's my logic:

The cpap machine probably measures apneas by detecting a stoppage of air flow, right? So, if I'm sleeping with a nasal mask, and leaking through my mouth, the air flow would NOT stop, even when I had apneas, so the machine would register LESS apneas if I were breathing thru my mouth, n'est ce pas?

By the same token, it seems like the machine detects leaks by means of pressure -- i.e., when operating correctly (without leaks), there is some resistance to the air being blown down my throat, but if I'm leaking through my mouth, there is less resistance to the airflow (it just blows straight out my mouth) and so it would register as a leak.

So, it seems like if I were mouth leaking I would see a DROP in AHI and an INCREASE in leak levels. Am I thinking about this right?

Min

Goofproof · Post by **Goofproof** » Mon Jul 31, 2006 10:28 pm

Not exactly. If you are leaking through your mouth, the pressure you need to open your airway, escapes through your mouth instead of holding your airway open. You then go into apnea and its recorded. Also if you have a APAP, you snore and the APAP raises the pressure to fight the snore, and that causes even more leaks, which makes for more apneas.

Dog chasing tail syndrome!

If you are mouthleaking AHI will go up, and the leak rate will too.

Sorry for the bad news, but leaking has to be controlled.

Don't shoot the messenger, Let Guest take a shot at me, while hiding! Jim

Mask

Additional Comments: Started CPAP June 14, 2006, pressure set at 8.0