Seemingly little correlation between EPAP (or PS) and AHI or flow rate. [UARS]

[Geer1]

As for next steps what did last nights data look like? If you are still seeing signs of lots of timed breaths I would try PSmin of 3. If recent results seem to be more normal that may have been an off night and you could try waiting a bit.

[ldinks]

Yes ASV without backup rate cannot treat centrals unless it is able to do so before the central apnea starts. In fact ASV without backup rate is likely counterproductive because just before the central apnea starts it would raise PS causing more CO2 to be washed out then once the central apnea starts the machine will do nothing (just like the day you had lots of CAs).

Yes as long as you use a range of PS the ASV will adjust PS to try and treat restricted breaths. Then when you have CA the machine will use backup rate to try and force you to breath.

The higher PSmax is the more powerful the machines attempts to correct central apnea, restrictions etc can be. The lower PSmax is the more handcuffed the machine is. If you want to be able to treat centrals the best you want PSmax to be high. Sometimes it might only take a PS of 3 to kick start a breath but other times it might take 6 or 10 etc. If PSmax is set high enough the machine will try higher PS as it believes is necessary. If you limit PSmax to say 3 or 6 then the machine may not be powerful enough to force you to breath (whether due to central, restriction etc).

UARS is a tricky beast and a lot of the symptoms are not specific to breathing issues although many people that get diagnosed with UARS then blame all their symptoms on it. It is possible that your UARS is treated and that you have lingering fatigue etc due to other health issues. Since you can't easily monitor UARS the best you can do is try the different settings available and see what seems to work best and then stick with it. In theory if your symptoms are due to UARS then higher PS creates higher flow rate and should provide enough ventilatory assistance for your body to overcome restricted airway, this is why Gideon was trying higher PS and hoping your body would adapt to it. My only interjection is that perhaps you should try a lower PSmin and see if letting the machine try to treat restrictions when they occur is more effective then just setting a higher PSmin which seems to cause more central related issues.

Flow rate issues do not always mean UARS. Flow rate issues can be present for a number of reasons. If they occur in a periodic nature throughout the night they could be related to REM sleep which always has worse flow rate graphs because part of bodies partial paralysis in REM sleep. Flow rate also gets affected by other things such as periodic limb twitches etc. Interpreting the cause of flow rate change is often very difficult and knowing if that is an issue or treatable is even more difficult.

Reduced respiratory drive is like the beginning of an apnea. You start taking slower/paused shallower breaths because your body doesn't think it needs to breath (due to low CO2 levels which is what drives spontaneous breathing effort). When you have backup rate on then this will mostly be seen as timed breaths. The machine is only forcing you to breath because your respiratory drive has decreased to the point where the machine thinks you need to breath more often. This is the reason that on that night you had lots of timed breaths and during many of them the machine was using higher PS because it was trying to not only force you to breath more often but to breath more deeply as well. This can be due to incorrect settings (if BPM was set too high) but in your case an auto BPM of 10 is low enough compared to your spontaneous BPM of 14-16 indicating it was a sign of reduced respiratory drive (due to average PS over 6).

Thank you for answering everything. I've written a lot below so I'll unfortunately not do you reply justice, but it has helped tremendously with my understanding of all of this.

I suppose I might not have UARS, just flow rate issues, but I'll lay out my experience to provide context for my belief:

- WatchPAT RDI above 5, before getting my machine.

- Lifelong sleep paralysis and exploding head syndrome, disappeared with machine use.

- Difficulty inhaling that alleviates significantly when moving my jaw, tongue, or looking up and not letting my jaw hang naturally loose. (I tried tongue and jaw oral things, didn't address the issue). Positional apnea was improved with a neck brace.

I think that's enough to say I have SDB, and I didn't/don't have anywhere close to the AHI to justify obstructive or central apnea. Machine data has never really shown O or CA events to be an issue (other than recently with the CA) so I think UARS is accurate.

And I believe I still have UARS because:

- I snore badly, even when close to underweight. This is improved as PS increases, still occurs a lot. 

- I move a lot in my sleep, talk in my sleep, twitch a lot, etc. This is improved as PS increases, still occurs a lot.

- Absolute worst days pre-machine (in terms of brain fog, struggle to wake up, back pain, depression, energy, tiredness, etc bundled together), disappeared with machine use, but my average day (still poor) pre-treatment is still what I experience now. It's like a scale of symptoms ranging from 5-10, and now it ranges 5-9.

- 24/7 yawning and bags under my eyes / looking tired, to the point that many bring it up because it's abnormal. More tired than anyone else seems to be. Oversleeping if I let myself. This is all still the case, just my "worst days", which were fairly uncommon, don't happen anymore. Again, 5-9 out of 10 rather than 5-10.

It's like my UARS would fluctuate day to day, but the worst 10% of days have now disappeared. My experience remains the same, without the unpredictability of a stray "worst day" and/or sleep paralysis here or there. My only other issue is some ADHD symptoms, which (possibly coincidentally) seem to match UARS/apnea but that's tricky territory, and I don't consider my ADHD symptoms related. It'll be a happy accident if they improve or disappear with further treatment. I'd only consider them a valuable part of this experiment with my settings if I noticed a big improvement, but a lack of progress on the ADHD front isn't a lack of UARS treatment, which I think is a fair way to evaluate that?

I'm also just wanting to fully explore my options here, because I've tried exercise, therapies, deits, meditation, living in different areas, all sorts of lifestyles, supplements, intermittent fasting, more/less socialising, hobbies, changing screen time, being stricter with my circadian rhythm, and much more. I've had a full physical, checking my organs, my thyroid, my hormones (incl test), my cholesterol, nutrition, etc. Never had issues other than B12 once, which I corrected immediately and is still good. 

Short of drugs to mask symptoms or becoming a mess for life, I can't think of what else to do. Doctors seem out of ideas too. But I had a home test that indicated UARS, treatment helped a few symptoms slightly and alleviated sleep paralysis, and there's room to push treatment further. It seems fair to pursue that. Not saying you don't think I should pursue this further, again I'm just providing context and my thought process overall.

As for next steps what did last nights data look like? If you are still seeing signs of lots of timed breaths I would try PSmin of 3. If recent results seem to be more normal that may have been an off night and you could try waiting a bit.

I've attached last night and the night before. Med PS of 4.13, looked better. Then last night med PS of 6.25, with a ton of timed breaths again, very similar to my bad day.

Given day to day variance in centrals, I think I'd adapt rather slowly (assuming I did adapt, too). Based on that and last night, a PSmin of 3 is worth trying to lower centrals? Looking at my history back in march, I even had similar centrals with a PS of 2, so I get a sinking feeling that these centrals will just forever be a factor if I want any PS at all. But one step at a time, eh.

Finally I've also attached a day I found back from near the start of my treatment. I had pretty good flow rate, but tons of timed breaths. OA and H events just due to not having a collar, I think, and FL events are mostly tagged where flow looks fine and/or during timed breaths so I don't think they apply. Maybe irrelevant but I figured there might be something useful in it.

[Gideon]

In this thread there is a history of flip-flopping approaches. let's simply follow one approach to either failure or success.
My goal with the ASV is simply using it as a tool for enough PS to manage the UARS which is really a very subjective evaluation.
If we were treating CA we would simply go back to a safe EPAP with a minimal PS of <= 3.0. so EPAP = 4, IPAP = 7, maybe adjusting for a higher EPAP and corresponding IPAP and possibly further dropping PS..
Higher PS values without question induce very significant CA events for ldinks.
These went away with BPM = Auto vs off. Let's simply try the current settings for a week then re-evaluate. Major question is Do you "feel" better?
At that point do we modify the ASV settings, extend the trial, or move to the std BiLevel approach of building tolerance for PS, which is the more conventional approach, or look for an appointment at one of Dr. Krakow's clinics that are very familiar with UARS and using ASV as a possible solution for them.

[ldinks]

Absolutely agree, I did think one thing at a time made sense but I trust you all more than myself. As you can see from my track record of other things I've tried, I haven't had the best of judgement lol.

Last three mornings, I've struggled to fall back asleep when my alarm goes off, which is new to me. Today I did, but I also only got 4 hours sleep. I found myself functioning better than I usually do on this little sleep. I'm more appropriately hungry and thirsty compared to normal, less tired later in the day than I expect. My stimulant medication has seemed more effective, which is a common thing I've read online today, with ADHD medication when resolving SDB. I'll keep my medication constant to not influence this week.

So far, I'd say I'm a little better overall, and it's starting to seem a little more noticeable and a little more consistent than placebo tends to be for me. Nothing drastic other than struggling to fall back asleep when I wake up, but this is a good thing because I can often lose an hour or even longer to conscious limbo.

Cautiously excited, put simply. I've felt this sort of improvement before and it has ended up being bust.

As for getting a proper trial with that doctor, this would be my preference. Unfortunately being in the UK I'd be paying entirely out of pocket, plus travel, and I'm a carer, just finished as a student, renting with a dog. My situation makes spontaneous international travel complicated, I doubt I can afford it at all, and then there's COVID restrictions on top. Maybe one day!

[ldinks]

Small update. I fell asleep without putting my mask on. Doh. Definitely noticed it this morning. 

I'll report back about the rest of the day when I next send some data but just going to keep things as-is for now as agreed. Preferably change up settings on Thursday night or so, allowing for maximum time to deal with any potential negatives by Monday.

[ldinks]

It's been over a week now. Felt a bit better, more energy, didn't get hit with a wave of afternoon tiredness, struggled to fall back asleep when I woke up, etc. But I Also seemed to undersleep most days by an hour or two. I felt far less impacted with this sleep deprivation, and even would say I felt better than I do when I have other settings and sleep the full amount.

The last few days got worse. Two nights ago I slept without my machine for a few hours (accident!), woke up, walked my dog, then slept almost 9 hours with my machine. Had massive brain fog and awful lower back ache, which was very common before my machine and non-existent the last few months. Today has been better but I still struggled to get up after 8.5 hours and slept another hour or so. 

I suspect oversleeping causes the fog and back issues, and was a bit of a fluke. But the following day wasn't great either, and the night before that was worse than the prior rest of the week. Anyway. My timed breaths are still there in huge blocks, although there's a trend of them decreasing over time. I might give it another week and just see what happens. My FL tagged events seem higher, the past four days. My gut is telling me I sleep better with more timed breaths. 

I've attached last night and two FL zooms. 

Shall I just do another week and see how it goes? Or shall I make a change now?

[Gideon]

Keep in mind that you don't need timed breaths, to need PS. BUT higher PS induced CA events for you and you need the ASV to treat the CA events caused by the higher pressure support.

I would hold these settings for another week.

[ldinks]

Yup, I just meant to point out that the last few days I've felt much worse and had less timed breaths (centrals predictively treated). I'm not sure why that is, though! 


How much longer now then? Just another week?

[ldinks]

Quick side question. I've got some mouth strips that are breathable etc. I tried one last night - it stayed on, I didn't have a dry mouth. I'd quite like to keep using them so I can start improving my dental health.

Shall I continue without them for the sake of not disrupting our data? Before last night, I never used them, and mouth breathing is my default.

[Crimson Nape]

If they work for you, "Go For It!". The object is to obtain the best therapy you can achieve.