Flow limitations (UARS)

[slowriter]

I think it's hard to know until we can get you sleeping for a few hours at a stretch.

[amouse]

As a matter of fact, I was finally able to sleep with CPAP last night! I slept from around 1:00-4:30 and 5:40-8:00.

The FLs are much better than they were, but still there. Also, still getting a lot of "CA" events prior to falling asleep, but no desaturations below 94. Below is the whole night of sleep, a close up of the initial set of "CA" events, and a close up of a period where I can tell I was asleep.

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[Miss Emerita]

Sounds like you've made significant progress! Although I favored a more gradual approach to introducing EPR, I'm inclined to say if you're comfortable with your current settings you should leave them alone for now, sticking with them for at least a week. It'll be valuable to keep track of how you feel during the day.

Maybe this is a moment to review the guidelines for sleep. I thought they didn't apply to ever-so-special MOI, but it turned out they did, and I slept better once I started following them.

• Keep a consistent sleep schedule. Get up at the same time every day, even on weekends or during vacations.
• Set a bedtime that is early enough for you to get at least 7 hours of sleep.
• Don’t go to bed unless you are sleepy.
• If you don’t fall asleep after 20 minutes, get out of bed.
• Establish a relaxing bedtime routine.
• Use your bed only for sleep and sex.
• Make your bedroom quiet and relaxing. Keep the room at a comfortable, cool temperature.
• Limit exposure to bright light in the evenings.
• Turn off electronic devices at least 30 minutes before bedtime.
• Don’t eat a large meal before bedtime. If you are hungry at night, eat a light, healthy snack.
• Exercise regularly and maintain a healthy diet.
• Avoid consuming caffeine in the late afternoon or evening.
• Avoid consuming alcohol before bedtime.
• Reduce your fluid intake before bedtime.

[amouse]

Thank you for weighing in, Miss Emerita! I will leave the settings for a week and check back.

And thanks for the reminders on sleep hygiene. The hardest one for me is getting up if I don't fall asleep in 20 min. I try not to clock watch, but even when I am aware it's been more than 20 min... I just feel so cozy in bed! But you are right that the guidelines apply to everyone, even moi... no matter how cozy I am.

[slowriter]

As a matter of fact, I was finally able to sleep with CPAP last night! I slept from around 1:00-4:30 and 5:40-8:00.

That's progress!

The FLs are much better than they were, but still there. Also, still getting a lot of "CA" events prior to falling asleep, but no desaturations below 94. Below is the whole night of sleep, a close up of the initial set of "CA" events, and a close up of a period where I can tell I was asleep.

What do you base this conclusion on?

It might be worth posting a two-minute close-up of the flow rate graph to see what it looks like, from a time during which you are sure you are asleep (like for this last night, around 1:30 or 2).

[amouse]

Hi slowriter! Here is the image you requested. I am curious to know what you are looking for in this...

Oscar Data Dec 13 - 2 min.png (187.41 KiB) Viewed 742 times

What do you base this conclusion on?

Which conclusion do you mean? When I am asleep and when I am awake? If so, I have watched a lot of videos and read a lot of threads on here. At the end of the day, it's just a guess without EEG, but my guess is this is awake:

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... and this is asleep:

Oscar Data Dec 13 - asleep.png (24.94 KiB) Viewed 742 times

Those guesses are also loosely correlated with my memory of when I was awake/asleep.

[slowriter]

Hi slowriter! Here is the image you requested. I am curious to know what you are looking for in this...

Evidence of flow limitation, which can cause RERAs.

The waveform should be smooth and rounded. See this article for more (particularly figure 5/table 1).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688581/

I don't consider myself an expert on evaluating these, but it does seem to me the example you posted shows evidence of FL.

[amouse]

Oh gotcha! I am basing that on the FL line on OSCAR. I didn’t know about the wave forms, but I’ll read about it. Thanks!

[Pugsy]

Your presumed awake example of the flow rate...I agree...you were probably awake. Lots of ragged breaths. Doesn't mean much since you were likely awake.

Now the other example where you were asleep...for the most part the breaths look normal but there were a handful that showed a very subtle change that might point to a flow limitation. They weren't classic though and certainly not very many of them.


Here's a large cheat sheet I use for help in evaluating flow rate breaths

[amouse]

Thank you, Pugsy! This is opening a whole world of flow curves that I was not aware of. I was just looking at the FL rate on my OSCAR data.

Ooook, now that I know what you are looking for, I have some additional samples. My first examples were smoother than most in my data. There is also a lot of this:

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Oscar Data Dec 13 - flow weirdness 3.png (19.81 KiB) Viewed 716 times

[amouse]

Hello! I am back with an update and another question.

Update: I have finally made progress falling asleep and keeping the mask on! I got interrupted to do my two-night HST before xmas, but I finally have a streak of nights where I've worn the mask from bedtime until morning. The breakthrough seemed to be after I bumped my pressure up to 9 min/max because I still felt like I was not getting enough air. It felt easier and more comfortable to keep the mask on all night at a slightly higher pressure (and I wonder if I should increase even more...). I have left my EPR at 3.

Question: What now? I plan to leave things alone for a few more days, but what will be the next step after that? From reading the forum, it seems like I should try to optimize based on (a) my subjective experience of feeling better and (b) smoothing out the inspiratory flow curve on OSCAR. I am certainly not feeling better yet (actually worse than without CPAP, if anything), but it's early. However, I am starting to somewhat prefer the machine and feel like I can breathe better with it, so that's something, I guess.

I am going to post a couple of snapshots from my OSCAR data from last night. Are these possibly undetected RERAs? I had around 3-4 of these an hour last night, but the machine only flagged the "CAs" associated with some of these instances. Should I eventually bump up the pressure and see if I get fewer of these? I have some portions of sleep where the inspiratory flow curve is nice and smooth, but still lots of flat, u-shaped, and chair-shaped breaths in other places.

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[Pugsy]

The CA/central flagged at 03:56...you were awake or at least not fully asleep as it obviously follows non asleep breathing.
Now why you weren't asleep...we don't know and have no way to know.

You are going to have to do detailed experiments and keep logs of how you feel...and take a big dose of patience pills to see if you need more pressure or not.
At least 2 weeks at a setting before changing things unless a change causes a big problem.

Subjective evaluations are very hard to do but you have to do them. What you see on the software isn't really going to help you very much...how you feel is the most important thing.

[amouse]

Thanks for the response, Pugsy. Dang! Objective metrics would make this a lot easier! But I appreciate the reality check and suggestions. I’ll try to use a phone app to create a data set for my fatigue.

On the images I posted, I recognized the arousal breathing after 3:56 but I wondered if that last breath before the big one was a little jagged... maybe not.

I see my sleep doc in late January. I’ll get my HST results. If she’s convinced I need xCPAP but I still don’t feel at all better on CPAP, would it be worth advocating to try BIPAP? I love pressure support and I have not had any “real” centrals (despite my love of holding my breath while awake). Or will it still be too soon to tell anything?

[Pugsy]

You are using the AirSense 10 AutoSet for Her with EPR on and set to 3...you are essentially using this machine like a bilevel machine (bipap is actually a Respironics marketing term for their bilevel machines)....so you are sort of using a "bipap" already.
The main difference between your current machine and a bilevel machine...the bilevel machine can go to 25 and your current machine can go to 20 (but you never come close so that's not something you need) and the bilevel offers what amounts to settings higher than EPR at 3 for you to try. Think of it as EPR choices higher than 3....it's called pressure support and we figure it a little differently but the end result is the same...bilevel pressures which just mean 2 distinct pressures...one for inhale and another for exhale.

So I am not so sure that going to bilevel would help you or not. Using 4 cm pressure support (EPR) might enable you to sleep a little better....and it might not. I will say this though....I like EPR of 3 but love PS of 4...and I do think I sleep a little better with PS of 4. Now it might be all in my head and I can't really document anything to prove it as it is all subjective. In addition there are a couple of other minor comfort settings available on the bilevel machines that aren't available on the AutoSet....would they help you or not????? That's an unknown and we have no way to know.

It would be nice if we had metrics to fall back on and use as a guide but with UARS we really don't have that luxury. Subjective evaluations are hard and take time and most of us want an immediate fix and don't want to take the time.

I have seen lots of UARS patients here over the years....documented for sure UARS and in almost every case they needed to use more pressure than the auto adjusting machines wanted to give for them to actually start feeling better. Remember the auto adjusting algorithm is for OSA and not UARS. So while your machine might only want to go to so and so pressure....it's not impossible that you need 2 or 3 cm more pressure for UARS (if that is what you have). I remember one woman whose machine only wanted to go to 9 cm and wouldn't ever go any higher....she eventually had an in lab sleep study with the Pes device and cpap so that she was actually titrated to the point where the UARS was treated and the pressure that she needed was 13 cm. It wasn't until she used 13 cm all night long that she actually started feeling better.

UARS is a bitch...I am so glad I have plain ordinary OSA...it's actually easier to treat IMHO because of those metrics.

[slowriter]

The Resmed algorithm, at least, does respond to flow limitations, which are at the root of both OSA and UARS.

I have a hypothesis that one good and simple starting point for self-titrating UARS is to adjust up the min pressure until the auto algorithm keeps the pressure relatively stable over the night, and then to go from there based on subjective feel.

amouse: as pugsy says, hard to know if you'd do better with a bilevel. Certainly I'd be prepared to discuss it with the doc, and in the meantime work on improving your compliance with the machine you have.