awakening and mouth breathing

[rgrxdp]

I suspect that I breathe through my mouth on occasion ( I wear a nasal mask ). How does that affect AHI or does it just show up as leak? Also, I wake up occasionally and remain awake thinking for a while. How does that affect AHI? If I get up to use the bathroom, shutting the CPAP off momentarily, will that affect the AHI?

[RonWessels]

Going through your list:

Does mouth leaks affect AHI? Possibly, depending on the severity of the leak. When the leak gets sufficiently large, the machine is no longer able to reliably determine apnea events.

Does being awake affect AHI? Probably. The machine does not know or care if you are awake or not. It will simply respond to its detection of your breathing patterns. Having said that, many people (myself included) tend to consciously hold their breath as they shuffle about on the bed. That will look like a clear airway apnea event to the machine, since all it sees is that you have stopped breathing and the airway appears clear. On the other hand, since the soft tissues that would block the airway are actually under voluntary control, you will not have any "true" apnea events while you are fully awake. This means that the total number of sleeping apnea events are divided by not only the time you are asleep, but also the extra time that you are awake, to obtain the average number of events per hour (or AHI).

Does turning the machine off and on again affect the AHI? Not significantly. It may skew the details of the running AHI value slightly (since time appears to have taken a jump), but the overall summary should be correct.

Did that help?

[zonk]

Hi rgrxdp
Try chinstrap, chinstrap helps keeps mouth closed and minimize mouth leaks
ResMed machines subtracts mask vents leak and report "unintentional leak" which made up of "mask leak plus mouth leaks" (for this reason you need to select the mask type) and their machines can handle leaks up to 24 L/m. Prolong leaks over this number affects accuracy of the data and the machine cannot distinguish whether apnea is obstructive or central so it score the apnea as unknown apnea. Data get recorded only while using the machine, frequents wake ups not only affect your sleep quality but also might raise AHI if apnea scored while awake as the machine have no way of knowing if you were asleep or awake.
You might want to look at detailed data, here is the download links to both ResScan and SleepyHead
http://www.apneaboard.com/forums/Forum-P...-and-Links

[PaulaO2]

I can look at the data on SleepyHead and tell the times I was awake. The pressure is way, way low for one. Drops like a rock when I wake up. Does the opposite when I go back to sleep. I tend to not remember anything I do when I wake up and then go back to sleep. Used to get me into a lot of trouble! The spousal unit would tell me what needed to be done that day then get mad when nothing got done. Finally told me something good would happen and I forgot about that, too so finally believed me.

So when I look at the data and see drops like that, then I know I must have woken up. Any central events that happen during that time, I ignore. There's almost always some central events, maybe a few obstructive if I am talking.