AirSense 11 settings to tweak to reduce central apneas?

[jsam]

I'm a male in my mid-40's, diagnosed with moderate OSA in August 2022. The sleep study showed a total of 2 OAs, 7 CAs, and 72 hypopneas over 5 hours of sleep. I've been using a ResMed AirSense 11 since September 2022. My OA numbers have been very good since I got used to the machine, but my CAs increased. I was put on acetazolamide (125mg) to see if it could bring down my CAs and I believe it was working but may have affected kidney function (increased creatinine) so I've gone off it now for a week. 

Overall, sleep has definitely improved with CPAP but I don't feel that well rested and would like to see if improving CA numbers has any impact.

The sleep medicine provider has offered to set up a lab titration study but is very backlogged, so I'm wondering if this group has any suggestions for settings I could attempt to tweak in the meantime to lower CA without increasing OSA or hypopneas.

I have been using the machine with EPR off for several months. My other settings are shown in the attached screenshot, as well as a typical night (37 CA events). I've also attacehd a graph of a rolling average of CA events from October 2022 to the present. You'll see in the past week the numbers have gone up a fair bit since I've been off of acetazolamide.

Thanks for any suggestions!

Settings
   

Events
   

Graphs
   

I'll follow up with another post with my rolling average CA count, since I can only attach three files to one post.

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Here's the graph of rolling-average CA's since October 2022.
   

[Gideon]

Let's try with your max pressure set to 8. A lot of your CA events are at higher pressures. Normally we would cut back on EPR but that feature is off

[jsam]

Thanks for the suggestion! Based on two days of data, CAs have dropped dramatically (only 7 total last night, thus less than 1 per hour) and OAs remain low. I'll report back in a couple of weeks when I have longer-term data.

Latest charts:

   

[Gideon]

Please include the left sidebar in your next screenshot, then we don't have to count individual events and divide by hrs used. It also includes your 95% FL which use as a gage of how bad your flow limits are.

[jsam]

Thanks for the feedback! Attached is an updated chart that should have all relevant information.
   

[jsam]

Sleeping last night felt quite rough, which appears to be corroborated by the data. I had the same settings as the previous two nights and nothing different lifestyle/behavior-wise. Are there any conclusions/theories I can draw from this?
   
One potentially relevant data point is I believe I woke up briefly around 4:50am after a nightmare, and was talking in my sleep 4:36-4:37am.

[jsam]

Thought I'd also add a close-up of one of the periods labeled CSR in case this is helpful.
   

[Caro2020]

I have very similar CA numbers.  Some nights are good but over last few weeks had a few around 50, most are during my last several hours.   My pressure is 5-20 but rarely go over 10, but maybe that's is too high and ramp at 5 minutes.  I can't figure out why I have the majority during those last several hours.   Hope you make progress to lower numbers.

[jsam]

After that recent bad night (AHI>7), my numbers have been better. Last night was the lowest I've hit (AHI<1). 4 out of 6 of the CAs were in the same hour. At this level, is it worth trying to figure out causes? Any ideas why (1) my numbers vary so much night-to-night with the same parameters and/or (2) what is special about the time when most of the CAs occur, early morning?
   

[quiescence at last]

I feel like 02/07 clip shows transitional CA at the wake sleep boundary, with multiple REM sessions:
(1) REM 04:11:50 to 04:13:25 followed by a wakish breath-holding at 04:13:30, recovery breathing and decent into sleep by 04:14:20, entering REM again by 04:15:20.
(2) REM 04:15:20 to 04:19:00 followed by a wakish breath-holding at 04:19:20, and immediate decent into mixed sleep, maybe waking a little in 04:21:45 thru 04:22:00.
(3) kind of REMish hyper-breathing 04:26:50 thru 04:29:30, some yuk, then hyper-breathing from 04:30:25 thru 04:32:25 followed by wakish breath-holding (the chair-looking pattern)

It is quite possible that the transitional CAs that seem to be occurring in last part of your sleep are being kicked off while brain is trying to enter REM cycles. REM is generally more prevalent in latest sleep cycles of the night, and REM periods generally increase in length.

I suspect you'll find some of the same behavior of fast sinusoidal shallow breathing (and I would say is REM) during these periods on 02/05 chart, at times:
(1) 02:18:00 thru 02:32:00
(2) 04:35:30 thru 04:52:00 which coincides with your report of wakening at termination of a dream.

I do not think you're CA occurrences are going to be detrimental, and think you are alright ignoring them for now.

QAL