Soon to start CPAP - Question on dehydration

[Sleeprider]

You might be in the same boat as Looking Forward in this thread. http://www.apneaboard.com/forums/Thread-...e-Centrals. She is about to start on ST-A (assured volume positive pressure), and has som similar neurological issues, actually a form of muscular dystrophy. Worth a read.

[picante]

OMG, those are long, clustered CAs she's got. I just started the thread, but will entertain myself with it tomorrow and learn to zoom. I know, the link is in your signature, Sleeprider. You've got the most useful signature!

Hopefully that will distract me from eat-nothing drink-nothing prep for the endoscopy at 1:30, grooooaaan. The bright side: if there's enough air in my guts, I won't be hungry at all!

I just found your post explaining postural & neck position. Yup, yup, and yup. I'm constantly adjusting my neck at night to arc it more. (My chiropractor does the same, only during the day.) Today's graphs show that it misbehaves while I'm sleeping.

All your info has been so welcome, Sleeprider. My learning curve is still swinging up, and everyone's suggestions have yielded more data to help me nail down what's going on. Today's lesson: daytime CPAP sessions can clear my brain fogggggg.

Feeling grateful!

[picante]

Friday I traded in my Dreamwear FF mask for a ResMed Airfit F20. Now I realize how badly the Dreamwear fit me, gawd.

I did not change my Autoset range (8-11) that night. The Airfit was blowing gently compared to the Dreamwear, which always seemed determined to blow my mouth open. It was a regular windstorm, even when I got a tight seal. And I spent a lot of daytime sessions trying to achieve the elusive seal.

Friday night was great, and my event count was waaaaaay down. Total time was higher -- 6h 24m -- bc I wasn't having as much stomach/gut pain.
CAs: 19
Hypopneas: 3
Obstructive: 2
RERAs: 2
For the first time in many months, I had no air hunger in the morning!! No brain fog, either. And I ate more yesterday than any time since I started CPAP. (My BMI is now below 17.)
Median pressure 10.96
95% 11.0

Saturday
I wanted to see what would happen if I raised the max. pressure. With the Dreamwear, I inched it up, and the event count rose. I wound up with 43 CAs both Wed. and Thurs. night. And 23 OSAs (19 on Thurs.), over only 4 1/2 hours. I thought it might be because I had to stop aspirin for a few days (for the endoscopy) -- aspirin mitigates my sinus inflammation.

Well, I only increased it from 11 to 11.2 cm last night. Total time 7h 24 m:
CAs: 50
Hypopneas: 6
Obstructive: 7
RERAs: 0

Today: gut-aches from aerophagia & brain fog are back and I can barely eat. So I'll put it back on 11 tonight and see what happens.
Median pressure 10.9
95% 11.12

Can anyone tell me what's going on? Is this possibly a threshold I've found, where going over 11.0 cm puts great gobs of air down my esophagus?
I can post graphs if needed.

[jaswilliams]

An increase in pressure is not the answer, more pressure will not sort CA’s please post some graphs as these provide us with valuable information.

[picante]

An increase in pressure is not the answer, more pressure will not sort CA’s please post some graphs as these provide us with valuable information.

There was only one reason for me to increase the pressure: the doc's prescription is for constant 12 cm. I started only on Thurs. the 29th and was already off the script by Saturday because of aerophagia so severe I could not eat. Called the doc Tues. the 4th, and he still hasn't called me back.

I've now realized that the mask I just swapped in was pretty leaky, although not as leaky as the Airfit F10 I was given for the sleep studies. So the titration for the sleep study was ... what? -- a throwaway result?

Will post graphs after I get some breakfast in me. Last night the numbers were back down, with the range set at 8.2-11.0.

[Hydrangea]

I got 4 hours of not the best sleep during my sleep study. So I'd venture to guess that they data they got was probably not the absolute end-all-be-all best data they could've gotten. So I take their Rx as a starting point.

[picante]

Screenshots for Friday, Sat. and Sun. Pressure ranges: 8-11 on Friday, 8-11.2 on Saturday, 8.2-11 on Sunday.
Friday was my first night on the new Airfit 10, and I had very little aerophagia (no gut-ache). Saturday night - lots of aerophagia, I should have shut it down early. Sunday night - some aerophagia, so I shut it down at 4:30 am. I'm able to eat this morning, yay!
Should I post any zooms? Other graphs? Sorry, I haven't learned to enlarge these yet.
[attachment=9350]          [attachment=9351]          [attachment=9352]

[picante]

I got 4 hours of not the best sleep during my sleep study. So I'd venture to guess that they data they got was probably not the absolute end-all-be-all best data they could've gotten.  So I take their Rx as a starting point.

OMG, good point. During my titration study I got 2 1/2 hours of sleep, which was an hour more than I got for the diagnostic study, LOL. Thanks.

[Sleeprider]

You might recall my original take for settings was 7-10 EPR 3. You chose to increase that to 8-11 and had pretty good results and comfort, but when you further increased maximum pressure, things went south pretty fast in both event rate and comfort. This was predictable, and I would have advised against it. Your events are mostly central, and your machine will respond to flow limitation to settle at the maximum set pressure. Fo you, auto pressure is kind of a fiction, because you really only see the maximum. There is a threshold form your lower esophageal sphincter (LES) to keep air out of your stomach, and you found it. Think of it like a spring-loaded door; in your case the LES blows open at pressure greater than 11.0.

Are you ready to try my originally suggested settings? I really think your comfort will be better at 10.0 and the CA event rate will drop with lower pressure.

[picante]

There is a threshold form your lower esophageal sphincter (LES) to keep air out of your stomach, and you found it.  Think of it like a spring-loaded door; in your case the LES blows open at pressure greater than 11.0.

Wow, thanks for explaining this, Sleeprider! On the Dreamwear FF mask, it blew open at 10.4 cm.  I know (in retrospect), because I tried a range of 8-10 after you made your recommendation. (Don't remember why I chose 8.) That was Dec. 3 and 4. From my notes, I see the aerophagia was much improved, but I had "massive brain fog" the morning of Dec. 5th, possibly from shutting the CPAP down so early to avoid more air in my guts -- I really really needed to eat.
I was dinking around with the mask seal during the day, so I zoomed these to just the nighttime.
[attachment=9353]          [attachment=9354]

Then I increased the max pressure to 10.4 (and hit that threshold, but didn't realize it). I put it up to 11 for 2 days, with catastrophic results, then I gave up on the mask and swapped it Friday.

Given that the Airfit F10 is a totally different ballgame, I could try the 7-10 range, but I'm wondering if my initial apneas of the night are worse because I've got my minimum set too low at 8. I'm also thinking the Airfit will give me less pressure at 10 than the Dreamwear, which was a veritable windstorm, even when I had no leaks, probably due to the much smaller facial surface area within the mask.

As you said, autopressure is a bit of a fiction for me. But I don't actually hit the max pressure before I have my first events.

Can you tell me whether the aerophagia is one possible cause of CAs? Or are the CAs a cause of aerophagia? Or both? I had only 3 CAs during my sleep study, the doc said. I slept 2 1/2 hours total, so if I sleep a normal amount of time, that would be about 9 CAs per night. Yet I had 43 CAs my last two nights on the Dreamwear FF at range 8-11.