Pressure/Ahi/Sleep Time Relation.

Hi ladies and gentlemen.

You were very helpful and insightful about my multiple questions when I started CPAP therapy almost a year ago, now I have other concern that you might be able to help with.

My whole adult life, I'm sleeping in at least 2 portions per night, like sleep 3-4 hours, then wake up (go to bathroom or just wake up without any need) then sleep again 3-4 hours. Or 3 portions, sleep 3 hours, wake up, sleep 3 hours, wake up, sleep an hour or two. Of course no matter how much time I spent sleeping I feel bad. I thought that would stop after I get my apnea managed, but it continued with cpap as well, although I have to say I feel way better with cpap, and while I still have hard few hours after I get out of bed, I'm not sleepy any more throughout a day as I was prior the therapy and my concentration levels elevated, also even people around me noticing I'm fresher.

We don't have sleep doctor specialists in my country to ask for help, and I'm trying to understand if this sleep behavior is related to my OSA or is it some other disorder.

After a lot of experimenting with pressures and masks, I found out that for my current mask (f30i), my "sweetspot" pressure is 10-16, any less than 10 I feel like I'm suffocating, and I'm not sure how would f30i handle pressure of 18 or 20.

I'm going to bed same-ish time and waking up same-ish time every day, so I'm not over the place with sleep hygiene, but last night I had a lot of work related stuff to do and I had to spend the whole night awake, so I went to bed at 8Am, and woke up on alarm 2:30 PM. I was sleeping 6+ hours in continuity and I'm feeling great.

However, I noticed in OSCAR that in last 2 hours of my sleep, max pressure was "clipping" and my AHI rose to 26 and was like that for an hour, this is the highest AHI I had since I started CPAP therapy. My usual AHI is 1-2 since I started using CPAP, I rarely go close to 5. For the reference, my home sleep study AHI prior CPAP was 45 while O2 saturation was a little bit over 70%, and that was on 3 hours sleeping sample, I guess it would be even worse if I was more relaxed and was sleeping longer.

Is this common that AHI and obstructions increase with sleep time ? Can that be a source for my problems ?

So should I unlock the max pressure and let it go to the max if it wants to ? Will f30i hold the max pressure when needed ? I also have Vitera, but seems that L cushion is too big for me, while I really enjoy Vitera mask, I have high leaks in OSCAR with it, I ordered M cushion to see if will improve, my understanding is that Vitera should handle high pressures if fits well.

Unfortunately, we don't have a sleep specialist doctors here to fine tune my therapy, so I have to ask you guys.

Thanks

PS: Here is my OSCAR data for the last night, this is all actually one sleep session, it got separated to 2 since I left the noon to be a "new day" in settings.

If I were in your shoes I would first try to figure out if those clusters of flagged events were real asleep events or arousal/awake related flagged events. If not asleep they don't count.

Watch the videos here...and bear in mind that while it talks about central apneas (ClearAirway on the OSCAR reports) false positive arousal flagging....it's not limited to just false positive flagging for centrals. We can have false positive OAs and hyponeas as well as centrals. These machine only measure air flow and they don't have any way to measure sleep status.
http://freecpapadvice.com/sleepyhead-free-software

Pugsy wrote: ↑

Fri Dec 24, 2021 9:03 am

If I were in your shoes I would first try to figure out if those clusters of flagged events were real asleep events or arousal/awake related flagged events. If not asleep they don't count.

Watch the videos here...and bear in mind that while it talks about central apneas (ClearAirway on the OSCAR reports) false positive arousal flagging....it's not limited to just false positive flagging for centrals. We can have false positive OAs and hyponeas as well as centrals. These machine only measure air flow and they don't have any way to measure sleep status.
http://freecpapadvice.com/sleepyhead-free-software

Hey Pugsy !

Will watch them. Thanks !

I guess I was asleep, because the machine also detected snoring during that time. And I do snore, a lot.

I have snored while half awake...just saying. I don't ever assume anything when I have facts available to help me know for sure and eliminate assuming anything. You know what they say about "assume".
Now sometimes we have to assume something because we have no way to verify...but in this situation you have flow rate evaluation to help you evaluate things better.

All that said...there are 2 reasons why we might see clusters like this and we are for sure asleep.
1...REM stage sleep
2...sleeping position...usually means supine sleeping
this is because it is common for OSA to worsen and need more pressure for either or both of these factors.

If you think you were for sure asleep...I would increase the max and see if allowing the machine to do what it wants to do will actually break up those ugly clusters (no matter what the reason).

I have a good example below where I circled the for sure asleep breathing in red....and all the stuff flagged in the non circled flow rate is awake/arousal related false positives. I don't remember being awake but that means nothing. We don't always remember awakenings or arousals.



or same time frame more zoomed out so you get a bigger picture of all the false positives and a big block of irregular breathing.

Pugsy wrote: ↑

Fri Dec 24, 2021 10:07 am

I have snored while half awake...just saying. I don't ever assume anything when I have facts available to help me know for sure and eliminate assuming anything. You know what they say about "assume".

Guilty as charged Few months prior starting my CPAP therapy I was snoring while awake, precisly while I was watching movies or tv shows with my wife, I wasn't aware I was snoring.

Pugsy wrote: ↑

Fri Dec 24, 2021 10:07 am

All that said...there are 2 reasons why we might see clusters like this and we are for sure asleep.
1...REM stage sleep
2...sleeping position...usually means supine sleeping
this is because it is common for OSA to worsen and need more pressure for either or both of these factors.

As far as I'm aware, I never sleep on my back, what could happen though, that I turned to stomach, I was doing that a lot in the past.

Pugsy wrote: ↑

Fri Dec 24, 2021 10:07 am

If you think you were for sure asleep...I would increase the max and see if allowing the machine to do what it wants to do will actually break up those ugly clusters (no matter what the reason).

I have a good example below where I circled the for sure asleep breathing in red....and all the stuff flagged in the non circled flow rate is awake/arousal related false positives. I don't remember being awake but that means nothing. We don't always remember awakenings or arousals.



or same time frame more zoomed out so you get a bigger picture of all the false positives and a big block of irregular breathing.

Would zooming in the event help evaluate what was going on maybe ?

Could some countereffect happen if the pressure is too strong ?

Thanks for your help Pugsy !

Morgoth wrote: ↑

Fri Dec 24, 2021 6:17 pm

Would zooming in the event help evaluate what was going on maybe ?

Maybe. But you need to zoom in so that you include the flow rate prior to the very first flagged event and you need to zoom in much closer than the approx 20 minute segment that you zoomed in on. Like maybe a 5 minute segment.
But looks like maybe the first OA might have been a real asleep event and the bulk of the rest of them were arousal related.
Maybe that first OA caused little wake up and it took you a while to get back to sleep.
The machine responds with more pressure because it can't tell awake events from asleep events and it thinks you had a truckload of OAs. It wants to go higher to kill them but it can't.
If they had been real asleep events the increase in pressure above the max might prevent more events but if they are arousal related...no amount of pressure is going to help them.
That's why I suggest at least letting the machine try to kill them and see what happens.

Just because you don't remember or think you were on your back doesn't mean it didn't happen.

Unless you were asleep prior to the 12:00 starting time...I don't know that this cluster is REM related because REM doesn't normally occur until around 90 minutes after sleep onset...plus you would be expected to have more than one REM cycle and we don't see other such clusters. Wouldn't be impossible I suppose.

Something changed during that 20 minute segment to cause you to need a lot more pressure if you were really asleep...or they are arousal/awake related false positives happening for some reason.
To fix a problem you first have to identify the problem...and figuring out if you were awake or asleep is critical.

If you happen to wake up during the night for any reason...reach over and turn the machine off and then right back on again that way you will have a break in therapy so you will have a for certain known awake time to look at and see if any flagged events are close to that break in therapy and you will know you can discount those.

Morgoth wrote: ↑

Fri Dec 24, 2021 6:17 pm

Could some countereffect happen if the pressure is too strong ?

No.