Auto to manual BPM experiment

[tmoody]

@tmoody

I'm following your thread with great interest, increased by the likelihood I'll be getting an ASV myself soon.

Thanks for sharing your experiment.

Bill

For what it's worth, since posting that last update my AHI has gradually climbed, for no apparent reason: 1.6, 2.0, 2.2, and 3.7. On each of these nights there was exactly one central. I say "for no apparent reason" but it's possible that it has something to do with a low-grade virus or something that I picked up from my grandson. Also, the weather in Philly turned warm and muggy, and I'd already removed the window AC unit, so the bedroom hasn't been very comfortable for the past few days. These are just guesses. In terms of machine vs patient triggered breaths, nothing has changed. I just have more hypos than usual.

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[tmoody]

Hmmm...another quick update. Last night's AHI was 5.8, with five centrals, the rest hypos. This was my "worst" night in well over a year (except for a couple of crazy jet lag nights while traveling overseas), although I honestly don't feel particularly tired today. And yesterday, after the unusually high 3.7, I also felt quite good all day. I haven't had the opportunity to look at the SleepyHead data yet for last night.

So, I'm puzzled by the steady increase in AHI over the last week. As I mentioned in the previous post, I had some sort of virus for a couple of days but that's gone now. I haven't changed any settings.

Dreammapper says I spent 1.3% of the time last night in large leak, but the night before it reported 0% large leak, so that's not the reason for both nights; it might have contributed to last night's high AHI. I apparently was doing some "popping" both nights, according to my wife, i.e., letting air escape into my mouth then popping it out and resealing.

The only other known variable is anxiety. I have something going on tomorrow (not medical) that I've been worried about for a long time, but my concern has escalated during the last week, since a meeting with a lawyer. Although I'm not aware of feeling more anxious than usual about it, I realize that these things often happen subliminally.

My plan, for the time being, is to change nothing and see what happens after tomorrow.

[Sleeprider]

I'm wondering if increasing BPM by 1, might reduce the hypopnea. The events may be related to the delay before the machine implements a backup breath.

[tmoody]

I'm wondering if increasing BPM by 1, might reduce the hypopnea.  The events may be related to the delay before the machine implements a backup breath.

That's a possibility, and the purpose of my experiment was to find the lowest BPM setting that would work. Currently I'm still at 6. Of course, that leaves the question of why the previous two weeks at BPM=6 showed very low AHI. It's possible that 6 is fine unless for some other reason things start to get rough, at which point 6 is to low for the machine to keep up.

As I said, I'll give it another night, since I'm not feeling too bad during the day. If AHI stays high or goes up again I'll either increase by 1 or go back to auto for a while to see what happens. Probably increase by 1.

[tmoody]

Another update: As I mentioned above, I have been worried about a legal matter, now successfully concluded. Having made no changes to settings, my AHI dropped from 5.8 to 1.7 and then 0.8, with one or two centrals each night. If nothing else, this experience has been a powerful demonstration of how much my mental state can affect my sleep. I'm not concerned about a few stray centrals sneaking through.

[Sleep2Snore]

People get obsessed with numbers, as long as you feel well and don't have tiredness or fatigue, is that what counts in the end?

Good to see you are getting on better now though.

[tmoody]

People get obsessed with numbers, as long as you feel well and don't have tiredness or fatigue, is that what counts in the end?

Good to see you are getting on better now though.

It's true, I think we fixate on numbers because they're there. I used a Resmed S8 for nine years at fixed pressure of 11 (at the start anyway; I don't know if the thing kept that pressure going the whole nine years). It was not a data-capable machine, so I had no idea what my numbers were. In fact, I didn't even know what AHI was, other than a kind of tuna. I felt fine.

[tmoody]

The odyssey continues...

I had set my machine to BPM=6 and pretty much forgot about my experiment. My average AHI was about 1.0 and I felt fine during the day, as long as I got enough total sleep. But about 10 days ago, after over two months at BPM=6, I decided to try lowering it again. My AHI immediately went up to 2.7 or so, and more centrals started happening.

AHI of 2.7 is not terrible, and I don't worry about a few centrals (although one night I had 10 of them, which I hadn't seen since switching to ASV). I still felt fine during the day. If anything I felt a bit more rested than I had with lower AHI at BPM=6, but the difference was subtle at best. I know we've had several threads about the extent to which AHI correlates with one's feeling of being rested.

Anyway, after five or so nights of higher AHI I pretty much figured I had "hit the wall" at BPM=5 and was about to set it back to 6, but I decided to let it go for at least a full week, since I wasn't feeling any ill effects. Interestingly, AHI started to drop again and the few centrals have become fewer. It makes me wonder if my brain just needed time to adjust to the new breath rate. In any case, the experiment continues. Unless things really go sideways I plan to leave it at BPM=5 for a while and see if the trend continues.

[SarcasticDave94]

You've got a very interesting experiment going here. Good to see the "feels better" trend of sleeping go up as you progress. In hindsight, I'm betting it's good for me that I received the ResMed ASV I did. A lot of mine is left in "autopilot" on purpose. It sounds like a PR has many more possible settings, which would be too tempting to me to try experiments.

Best sleep to ya,

Dave


PS: After 3 months on the ASV machine, I've got AHI avg of 2.1 which is down from my starting PSG number of 70+. Also just beginning to feel more rested, and getting over 5 hours sleep a night. Big improvements for me.