[CPAP] Confused with CPAP struggles and results

[dohm]

I had a home sleep study in 2021. Diagnosed with OA with AHI of 20.8. No CA, only OA and H. Suggested CPAP of 5-16cmH2O with EPR 3. I will attach results of study in reply since limit is 3 attachments. 

I tried CPAP for a few weeks back in 2021 but gave up on it due to difficulty wearing mask, sleeping and feeling worse in morning. Since daytime sleepiness and brain fog are interfering with my concentration and work, I decided to give it another try. Based on my attempts in 2021, lower pressure setting were the only way I could fall asleep. 

I started with a min pressure of 6.8 and max of 9 cmH2O with EPR=2. I had leak issues with old mask so replaced with new one and the was fixed. My first night (1/31/2024) with new mask was not good, but I forced myself to wear it most the night (maybe not a good idea). It was a very restless night and I felt terrible the next day. Reading that lowering EPR and pressure helps with CAs I changed setting to pressure min = 6, max = 8 with EPR = 1. I also removed mask when I could not sleep and put back on when I awoke again (2/1/2024). I felt pretty good the next day. I kept the setting identical the next night (2/2/2024), but struggled a little more with sleep. 

Questions: 
I do not seem to have any (or very little) obstructive apnea in my OSCAR results. In the past (similar to 1/31/2024) I get a lot of CAs with higher pressure settings (ofter CAs >15-20 per hour). I realize many of these might be during restless sleep or movement. I move around a lot while sleeping. How do I confirm if I really have OA and not just CPAP induced CA or real CA?

Is my flow limits a problem? How can I fix without increasing pressure and also increasing CAs dramatically? Is altitude giving me problems?

Thanks - Dave

   
   
   

[dohm]

Sleep Study attached.

[dohm]

One correction to sleep study - I do not seem to audibly snore. My wife never hears me snore, unless sick with cold, etc. I never wake up from snoring, etc.

[Luka07]

I am having almost the same ahi and also cca 30% snoring, but I dont snore that you can hear it.

In the sleep study they are measuring vibrations on the neck so that does count as snoring.

[dohm]

Trying again for any advice if available. 

Since my machine was spending most sleep time at max pressure I have experimented with incrementally increasing the pressure to see what changes with apneas and flow limits. I also added a Wellue o2 ring to monitor my oxygen. I am also wearing a collar the past 3 nights. It does help keep my mouth closed.

I still have very little to no OA as detected in Oscar, but a lot of CA and some H events. I have become more comfortable with wearing the full face mask longer (last night 8 hours!). I usually remove for a bit during night to sleep on stomach for an ~hour. My sleep is often restless and I shift around a lot. My O2 does drop below 90% (less than 1% time) and as low as 85% nadir. O2 stays higher while CPAP is on than when off. Also, I am in Denver so altitude might play a role. My pulse rate runs low too - around 50bpm a lot, always has. Wore a provided chest sensor for a week and Cardiologist said it is not a problem since he heart works well during vigorous exercise too. 

I have attached the last two night Oscar charts. Should I keep increasing my pressure, or back off again until centrals get under control. My flow waveforms often look a little flat and oscillatory too. I'm still confused.... Any help is appreciated.