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ResMed AHI Calculation - goodn - 07-31-2019
This may be stupid question- but during the course of sleep with a full face mask- if you quickly and gently lift the mask to say scratch or wipe you nose or scratch a covered portion of your face- all this with a quick motion without complete decompression of the positive pressure in the mask- could this be interpreted as a hypopnea episode on the CPAP software?
Would this represent a partial decompression and could theoretically be interpreted as a hypopnea by the CPAP software until full pressure is restored?
Hope I am not wasting everyone's time with this question.
RE: ResMed AHI Calculation - Hydrangea - 07-31-2019
If you lift the mask to get under it, I believe it'll show as a leak.
RE: ResMed AHI Calculation - sheepless - 07-31-2019
I agree it'll show up as a leak. it's also easy to imagine one might pause or restrict their breathing either in response to the itch or in the 'exertion' of moving to scratch, similar perhaps to a vocal or voiceless sigh or grunt or moan of complaint. that might score an hypopnea or apnea or flow limitation. even a snore. of course we don't worry about the stuff that happens while awake or in sleep/wake transition.
RE: ResMed AHI Calculation - goodn - 07-31-2019
Interesting- the motion is so quick and trivial it does not register as ax leak but the pressure wave us somewhat depressed thus registering as hypopnia- AHI is more on itchy nights?
RE: ResMed AHI Calculation - Sleepster - 07-31-2019
(07-31-2019, 06:16 AM)goodn Wrote: - all this with a quick motion without complete decompression of the positive pressure in the mask- could this be interpreted as a hypopnea episode on the CPAP software?
The high leak rate will cause the fan to speed up in an attempt to keep the pressure constant.
To score as a hypopnea (or apnea) it has to last for at least 10 seconds. What you describe doing doesn't sound like it lasts for anywhere near that long. It would be easy enough to tell, though. Just look at the data generated when you do it!
Quote:Would this represent a partial decompression and could theoretically be interpreted as a hypopnea by the CPAP software until full pressure is restored?
Hypopneas and apneas are defined in terms of flow rate, not in terms of pressure. The sensors are inside the CPAP machine, so that's where the measurements are made. Look at a flow rate graph. It oscillates up and down. The flow rate is positive when you breathe in (by convention) and negative when you breathe out. The peaks and valleys of that graph have to fall below some specified percentage (50% for a hypopnea, I think, although I've seen different numbers in different sources) for at least 10 seconds.
Quote:Hope I am not wasting everyone's time with this question.
Well, if we can help you you're not wasting our time. That's what we're here for, this is a support group.