Sensitive to flow limitation after 6h of sleep

[McPhearson99]

After enabling EPR 3 on my Airsense 10 Auto, I finally am able to fall asleep at the beginning of the night consistently and get at least 5.5 to 6 hours of sleep.
I usually wake up around 3:00AM for some reason, after 3 REM cycles (I'm counting REM cycles based on patterns I see in tidal volume and respiration rate). I can fall back asleep easily after waking up but often wake up again with a gasp or sharp inhale about 15 minutes after closing my eyes again. This pattern then repeats for hours until I either finally fall asleep for another REM cycle or I give up and wake up. Sleeping on my left side instead of on my back doesn't seem to help. I have not tried sleeping with no pillow.

I also noticed that my throat feels somewhat irritated when I wake up at 3AM and I'm thinking this could possible be related but I am not sure what to do about this nor if it's causal or a symptom.

Current settings: 9.0 min pressure, 16.0 max pressure, EPR 3 always on, humidifier 3, ramp disabled.
I've attached screenshots of OSCAR. The last small cluster of flow limitations coincides with the time when I fell asleep properly for an hour or so. I powered off the machine twice to get water and a cough drop to see if that helped (it didn't).

What should I change or what should I try to avoid the 15 minute sleep loops?
I also have an old VPAP 3 I can run tests with if anyone thinks a BiPAP would help instead of an APAP.

[gainerfull]

If you can retake your screenshots with the details tab up instead of notes that would provide more info to give a recommendation for next steps.

Looking for flow limit 95%, leak 95%, pressure etc.

[McPhearson99]

My mistake. See attached for the details pane. The Airsense consistently doesn't flag the wakeup events. I can tell when they happened because there's a sudden peak in the flow rate waveform and I take a screenshot of my phone to record the time (see second attachment for an example).

[Gideon]

It could be PLM

Video your self and see if these events coincide with sudden limb movements.
Periodic or restless leg movement can be treated with meds, but see if you can make the link first.

This is typically diagnosed during an In-Lab Sleep test.

[McPhearson99]

I had a sleep study done about a year ago, results attached. I do not know if the amount of limb movements I had is high or not at 29 (4 periodic). Given the amount of times I woke up during the study, I do not think it was particularly high.

I will try tonight to lower my minimum pressure. I noticed that most of the night I'm at my minimum pressure except for when I go into REM sleep, so my thinking is that lower minimum = lower total airflow = less irritated/sensitive throat. I will record the amount of times I wake up after the initial 6 hours and compare it to the 6 wakeups after the first 3 REM cycles I recorded last night. I'll also record myself on video to see if I can spot any limb movements.

[McPhearson99]

After a couple of weeks recording myself on video and journaling my sleep, I can confidently say that the wakeups aren't PLM-related.
I've narrowed down the cause to one of two things: either I have a low arousal threshold by default or I develop one due to throat irritation after 6 hours of APAP use or from some other cause. I've turned up my humidifier as high as it'll go without causing condensation in my mask but this doesn't seem to help.

This is theory is consistent with my observations that Advil, Zzzquil (NyQuil but only contains the sleep aid), and alcohol help me stay asleep. My guess for why these work is that the first reduces throat inflammation from any irritation and the last two raise my arousal threshold. Alcohol was a surprise here: despite the fact that it makes sleep quality worse I end up feeling more refreshed because I don't wake up as often.

Long term, I'd rather figure out a better strategy than taking 2 Advil before bed and 2 more when I wake up at 3AM to make it to 7AM but it'll do in the short term.
I'll give a BiPAP a shot since I read the "UARS and BiPAP" article on the wiki and I still have an old VPAP III. I'll start with an EPAP of 10, similar to what I'm currently using on my APAP, and a PS of 6.

[Hodgebot]

Any updates during the last two weeks? Was curious if you figured it out.

[McPhearson99]

I made two changes that eliminated 95% of those early wakeups: switched to a BiPAP (settings below) and started doing neck exercises. The second I started doing more out of vanity than to help my apnea but I think it may have helped. I'm definitely sleeping better and for longer periods uninterrupted after making these two changes. It took me a while to get used to the higher pressure support compared to my AirSense 10's EPR of 3.

Machine: ResMed VPAP III
IPAP: 13cmH2O
EPAP: 8.6cmH2O
Rise time: 300ms
IPAPmax: 3.00s
IPAPmin: 0.30s
Humidifer at the highest setting it can go without causing condensation, in my case 3.5/5. Having an EPAP of less than 8.6cmH2O resulted in too many CAs and I am considering raising it a bit more to 8.8 or 9.0cmH2O

I have not tried going back to my APAP to see if using a pressure setting of 13cmH2O and an EPR of 3 produces similar results, but I will do so in the coming week or two.
Overall, it was a good decision to try switching, if only because it made me re-evaluate my machine settings from scratch.

[Hodgebot]

Appreciate the in-depth reply, and good to know that things are much improved! My graphs and symptoms looked a bit similar and will be getting a second sleep study in two weeks, with the thought that I might move from CPAP to BiPAP. Hopefully that works for me as well as it did for you.

[McPhearson99]

Best of luck!
As a stopgap, you can try finding a used BiPAP on a site like Craigslist or convincing your PCP or sleep doctor to prescribe eszopiclone or trazodone. These two have been studied in apnea patients and they seem to increase the arousal threshold resulting in less wakeups. Given that alcohol increased my arousal threshold, I think a proper hypnotic would also work well and it may work for you.