Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

ResMed AHI Calculation
#1
ResMed AHI Calculation
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.
Post Reply Post Reply
#2
RE: ResMed AHI Calculation
If you lift the mask to get under it, I believe it'll show as a leak.
Post Reply Post Reply
#3
RE: ResMed AHI Calculation
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.
Post Reply Post Reply
#4
RE: ResMed AHI Calculation
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?
Post Reply Post Reply
#5
RE: ResMed AHI Calculation
(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.
Sleepster

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  A question about calculation using OSCAR-reported "Med." values as variables 2SleepBetta 8 1,294 04-11-2022, 09:56 PM
Last Post: Geer1
  MYAIR TIME CALCULATION? srlevine1 8 2,020 07-22-2021, 07:13 PM
Last Post: srlevine1
  AHI Calculation Gary K 21 8,916 10-15-2014, 02:17 PM
Last Post: bwexler
  Leak Rate Calculation PaytonA 8 10,588 02-27-2014, 05:28 PM
Last Post: robysue


New Posts   Today's Posts


About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.