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Help understanding Sleep study
Posted: Sat Jan 07, 2023 10:34 pm
by Centennial1
I just got a sleep study and have a few questions:

- 12-2022 Sleep study.jpg (63.97 KiB) Viewed 1805 times
How many Obstructive events were observed?
How many Hypopna events events were there?
How many clear airway events were observed?
What exactly is pAHI4% and PAHIc4% ?
About oxygen desaturations, am I reading this correctly, there was one event where the O2 dropped between 10 and 20 percentage points from some value. And the saturation was less than 85% for six seconds.
Can anyone help on any of these questions?
Re: Help understanding Sleep study
Posted: Tue Jan 10, 2023 12:35 pm
by dataq1
I deliberately did not reply to Centennial's question to see if anyone else had an answer.
Centennial's question about how many hypopnea events occurred can not be answered because the WatchPat study did not measure any flows at all, consequently it can not classify any patterns/events at all, not Obstructive, not Clear Airway obstructions, and no Hypopnea events.
IMO, Watchpat studies as this one are making the grand assumption that changes in arterial blood flow in the finger is caused by respiratory distress. That seems to ignore any other cause of transient arterial tone in the finger.
Be glad to hear any contrary opinions.
Re: Help understanding Sleep study
Posted: Tue Jan 10, 2023 2:04 pm
by lazarus
Your estimated AHI for the night was 16.9, so that means the test successfully discerned you may benefit greatly from trying PAP therapy. That is success!
Although, from your other posts, you are already using PAP, it seems.
That estimate of AHI is not based directly on breathing, so differentiation between hypopneas and apneas is not provided.
It appears there was only one event that the device considered central. (pAHIc)
Your sustained O2 shows you were below 90 percent saturation for only 2.4 minutes. Nevertheless, you may find your sleep (which is the point) will be greatly improved using PAP, once your pressures are optimized.
Not sure how this thread was missed before. Sorry about that.
Re: Help understanding Sleep study
Posted: Tue Jan 10, 2023 10:30 pm
by Centennial1
lazarus wrote: ↑Tue Jan 10, 2023 2:04 pm
Although, from your other posts, you are already using PAP, it seems.
In truth, I am asking this question on behalf of my brother, who didn't want to create his own login and thread, and asked me to ask those questions about his new sleep study.
I can understand his confusion, as he has heard me talking about apnea events and hypopnea events in relation to
my therapy, so he was surprised when his sleep study did not have any of those events observed. Incidentally, his wife's home sleep study, done about six months ago, actually did list the number of hypopneas, obstructions and clear airway events.
Re: Help understanding Sleep study
Posted: Tue Jan 10, 2023 11:45 pm
by lazarus
Centennial1 wrote: ↑Tue Jan 10, 2023 10:30 pm
on behalf of my brother
I hope he gets a full-data treatment machine so he can see that information during treatment and use it to optimize his therapy for the best sleep.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:08 pm
by Centennial1
Thank you (and my brother I'm sure is grateful for your good wishes), however that doesn't answer the original question about "events".
I hope he gets a full-data treatment machine so he can see that information during treatment and use it to optimize his therapy for the best sleep.
I've told him to hold out for a Resmed Auto 11. with an sd card, so he can monitor how his treatment is progressing, but he (and I) would like to know what his untreated values were/are to see the impact of his treatment objectively.
I'd like to focus on your comment that "that estimate of AHI is not based directly on breathing,".
In another forum, a contributor there said that the pAHI
does not use breathing at all, but relies on arterial blood in the finger and
infers conventional measures. Is that correct?
Hopefully, one last question,
if the WatchPat does not measure breathing how does it detect a clear airway apnea (as in pAHIc), assuming I've understood your comment ,"it appears there was only one event that the device considered central. (pAHIc)" ?
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:20 pm
by Rubicon
Centennial1 wrote: ↑Wed Jan 11, 2023 2:08 pm
In another forum, a contributor there said that the pAHI
does not use breathing at all, but relies on arterial blood in the finger and
infers conventional measures. Is that correct?
Yes.
Hopefully, one last question, if the WatchPat does not measure breathing how does it detect a clear airway apnea (as in pAHIc), assuming I've understood your comment ,"it appears there was only one event that the device considered central. (pAHIc)" ?
The new WatchPAT has an enhanced Snoring and Body Position (SBP) sensor that senses chest movement. Apnea + No Movement = Central Apnea.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:22 pm
by Rubicon
Centennial1 wrote: ↑Wed Jan 11, 2023 2:08 pm
...
infers conventional measures. Is that correct?
Except for oximetry, which it confers instead of infers.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:23 pm
by Rubicon
Or maybe refers.
Certainly doesn't defer...
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:33 pm
by lazarus
Perhaps, the report infers what the data imply?
Thanks for the posts, Rubicon.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 2:51 pm
by Centennial1
@rubicon,
the care that has to taken in comparing AHI from the WatchPat and a AHI from your home machine is that the one infers/implies apneas while the other actually detects apneas and hypopneas ..... is that fair to say?
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 3:44 pm
by Rubicon
Centennial1 wrote: ↑Wed Jan 11, 2023 2:51 pm
@rubicon,
the care that has to taken in comparing AHI from the WatchPat and a AHI from your home machine is that the one infers/implies apneas while the other actually detects apneas and hypopneas ..... is that fair to say?
I have NFI what that means.
That said, once you're "on a machine" you've introduced therapy and a whole new variable so the data is somewhere between mildly to entirely different.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 3:46 pm
by Rubicon
lazarus wrote: ↑Wed Jan 11, 2023 2:33 pm
Perhaps, the report infers what the data imply?
That's precisely the approximation that I hoped (wished) might happen.
Maybe.
Or not.
You heard weed is legal here now?
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 3:48 pm
by Rubicon
Rubicon wrote: ↑Wed Jan 11, 2023 3:46 pm
You heard weed is legal here now?
Going over to CostCo now to pick up a bale.
Re: Help understanding Sleep study
Posted: Wed Jan 11, 2023 4:02 pm
by Janknitz
This is a summary. The Watch Pat produces a much more detailed report, he should ask for the full report. It might be more clear from that.