Understanding my long-running issues with CPAP and BiPAP

Hi! For a long time, I've had sleep breathing issues causing daytime headaches and sleepiness. Over the past few years, I've done many week-long to months-long trials of CPAP, and more recently BiPAP. Unfortunately, I have never felt better using either of those, and in fact, generally felt worse, to the point where I gave up for long periods of time. In the past I've tried alternate methods as well (mandibular advancement device, tongue stabilizer, nasal sprays, etc.), sadly never feeling better , so I'm now trying BiPAP again.

In the past, I have tried a variety of masks, pressures, chin straps, mouth taping, etc. A few other pieces of info:
- I have had several sleep studies in the past, showing AHI anywhere from 8-15.
- I have a video recording system that I use to monitor my sleep. When sleeping without PAP, I see frequent breathing-related awakenings, and other unexplained awakenings (could be breathing, but it's hard to tell). When sleeping with PAP, I still see a lot of awakenings -- it's harder to tell if they're breathing-related (because of the mask), but I suspect many of them are. The remainder are definitely caused by the general discomfort of the mask, or minor leak/air noises, but overall I would say I don't have too many problems tolerating PAP.
- I have problems with keeping my mouth closed during sleep. Early on this was a big problem, so I now use either 1) full face mask or 2) nasal mask with mouth taping or chin strap.
- These days, I am using BiPAP (AirCurve 10 VAuto BiLevel)
- The AHI reported by the machine varies wildly, but from what I've heard it's not particularly reliable anyways, so I haven't been reading much into it.
- I raised the Max IPAP recently (from 14ish to 21.0) to see if it would make any difference (my understanding is that it just gives the machine a potentially higher max pressure to work with, if needed), but so far it feels the same to me.

Overall, I suspect that the nature of my obstruction is such that PAP is having trouble helping me (floppy epiglottis or something else more on the UARS side of things?), but I'd really appreciate if anyone could help take a look at my OSCAR data and tell me if there's anything obvious going wrong.

Here is some historical data with a few short trials I ran in the past year:


...And here is my latest night. Again, this was using AirCurve 10 VAuto BiLevel and Evora full face mask, Max IPAP 21.0, Min EPAP 12.0, PS 4.4. I felt like this was a pretty average night, which means I didn't feel particularly good today . I had a bit of leak/noise/comfort issues at points, but nothing major. I'm mainly curious if this shows evidence that PAP is not adequately treating my breathing problems.



Please let me know if any other info would be useful. Would really appreciate any help anyone can provide!

Do you take any medications that might suppress respiration like some sort of pain med??

At what altitude to you live?

When you tried the other machines did you use any sort of exhale relief? Something that made you have a different pressure on inhale than what you had on exhale?

Pugsy wrote: ↑

Thu Jan 04, 2024 10:15 pm

Do you take any medications that might suppress respiration like some sort of pain med??

At what altitude to you live?

When you tried the other machines did you use any sort of exhale relief? Something that made you have a different pressure on inhale than what you had on exhale?

Hi Pugsy, thanks for taking a look.

I don't take any medications that affect respiration (the only thing I'm taking currently is Finasteride 1mg).
I don't live at high altitude, I'm basically at sea level.
When I was using CPAP (ResMed Airsense 10), I don't think there was exhale relief, or it was very mild. I recall having trouble adapting to exhaling against pressure initially, but I eventually learned to tolerate it.

Tell me about the sleep studies you have had.
Home sleep study or sleep study done in a lab with a tech in attendance???
Have you ever had a sleep study done in a lab with a tech while using cpap in an effort to determine optimal therapy pressures?
Do you have a copy of any of those sleep studies results?

If a home study.....did you wear any sort of belt around your chest or abdomen?

How was it determined that you need to use the pressure settings you are using now? Who came up with these settings?

Exhale relief was available on the first AirSense 10 CPAP. It is called EPR which is Exhale Pressure Relief and is limited to a max of 3 cm difference. Can't tell for sure if you were using it from the graphs but it looks like your AHI has always been mainly central apneas. I am thinking you probably were using EPR though. It also looks like you always have been using higher pressures.

I know lots of questions and I probably will have more.
But I am trying to tease out information about those central apneas we are seeing on your reports. While an occasional central is normal and no big deal....you are having way too many of them IMHO which begs the question....what is causing the centrals???
Mainly did you have central apneas prior to starting on the cpap trials or did the centrals pop up only after starting cpap???
Knowing that information would help us in figuring out what we are dealing with here...obstructive sleep apnea or central sleep apnea or combination of both. It's important to know because how we deal with either obstructive apnea or central apnea isn't necessarily the same way....higher pressures won't help with central apnea and could even make them worse if the cpap pressure itself is the trigger. Using EPR or PS can also trigger central apneas in a very small percentage of people who start cpap therapy for obstructive sleep apnea and they didn't have a problem with centrals prior to starting cpap.

Your current settings are doing a great job preventing the obstructive stuff (OAs and hyponeas) and it wouldn't be impossible for those higher pressures to be actually causing the central apneas....also wouldn't be impossible for the bilevel pressures themselves to be causing the centrals. At this point I am mainly on a fact finding mission though because to fix any problem we first have to identify the cause of the problem. That's why so many questions........fact finding. Trying to figure out if you had the centrals prior to starting cpap or if cpap triggered the centrals.

I do have some thoughts about your settings though and those thoughts depend on what is causing the centrals.
Are you comfortable with making changes to your settings yourself or do you prefer a doctor's involvement???

How old are you and where do you live (as in country)?

Pugsy wrote: ↑

Fri Jan 05, 2024 5:46 am

Tell me about the sleep studies you have had.
Home sleep study or sleep study done in a lab with a tech in attendance???
Have you ever had a sleep study done in a lab with a tech while using cpap in an effort to determine optimal therapy pressures?
Do you have a copy of any of those sleep studies results?

If a home study.....did you wear any sort of belt around your chest or abdomen?

How was it determined that you need to use the pressure settings you are using now? Who came up with these settings?

Exhale relief was available on the first AirSense 10 CPAP. It is called EPR which is Exhale Pressure Relief and is limited to a max of 3 cm difference. Can't tell for sure if you were using it from the graphs but it looks like your AHI has always been mainly central apneas. I am thinking you probably were using EPR though. It also looks like you always have been using higher pressures.

I know lots of questions and I probably will have more.
But I am trying to tease out information about those central apneas we are seeing on your reports. While an occasional central is normal and no big deal....you are having way too many of them IMHO which begs the question....what is causing the centrals???
Mainly did you have central apneas prior to starting on the cpap trials or did the centrals pop up only after starting cpap???
Knowing that information would help us in figuring out what we are dealing with here...obstructive sleep apnea or central sleep apnea or combination of both. It's important to know because how we deal with either obstructive apnea or central apnea isn't necessarily the same way....higher pressures won't help with central apnea and could even make them worse if the cpap pressure itself is the trigger. Using EPR or PS can also trigger central apneas in a very small percentage of people who start cpap therapy for obstructive sleep apnea and they didn't have a problem with centrals prior to starting cpap.

Your current settings are doing a great job preventing the obstructive stuff (OAs and hyponeas) and it wouldn't be impossible for those higher pressures to be actually causing the central apneas....also wouldn't be impossible for the bilevel pressures themselves to be causing the centrals. At this point I am mainly on a fact finding mission though because to fix any problem we first have to identify the cause of the problem. That's why so many questions........fact finding. Trying to figure out if you had the centrals prior to starting cpap or if cpap triggered the centrals.

I do have some thoughts about your settings though and those thoughts depend on what is causing the centrals.
Are you comfortable with making changes to your settings yourself or do you prefer a doctor's involvement???

How old are you and where do you live (as in country)?

No worries, ask as many questions as you like, I'm happy to answer! Really appreciate your help.

Regarding sleep studies, I've had many over the years. Most of them were in-lab with a tech (and indeed, there was a chest/abdomen belt), and they didn't report anything unusual other than mild-moderate apnea (8-15 AHI as mentioned before). I did have two WatchPAT take home studies last year, which interestingly enough, looked great and said I didn't have apnea -- but I trust that data less than in-lab studies, obviously. Unfortunately, they didn't give me detailed data/graphs for all of them. The most complete data I have is for the first titration study that was performed in late 2022, when we decided to switch from CPAP to BiPAP. Full data is in the images below. This was a split CPAP-BiPAP titration study, as you'll see in the graphs.









The gist of what my doctor said after the above study was that it didn't seem like I needed very high pressure to fully control the apneas/hypopneas. Subjectively, I felt like I was still waking up a lot that night (although some of it was the lab setup, mask not tightened enough, etc.), and we noted that I didn't get much REM.

This study was used to determine the initial BiPAP pressure that I used, but since then my doctor tried one or two other sets of pressures. I haven't felt any different with any of them. For reference, the latest pressure settings they gave me were: Max IPAP 14.0, Min EPAP 8.0, PS 4.0, Ti Max 2.0s, Ti Min 0.3s. The newer pressure adjustments are my own, but I'm not knowledgeable on the topic -- I mostly wanted to try increased pressure to see if that would help.

Also, I had a more recent in-lab study (unfortunately, I don't have the data for that one, though I could maybe get my hands on it) where they said PAP was having trouble controlling my apnea.

What you mentioned about central apneas is interesting. No one ever mentioned central apneas being found during my sleep studies, only obstructive. However, I had recently noticed central apneas reported by the machine/OSCAR, and I asked my doctor about them. They mentioned that the central apnea reporting can be pretty unreliable, but we agreed that it would be worth trying an in-lab study with an ASV to see if that helps. I'm actually doing that in a few weeks, so hopefully I'll have those results soon-ish. Finally, this is maybe a bit anecdotal, but on a few occasions as I was falling asleep (but still awake) using BiPAP, I noticed that I stopped/delayed breathing for a few seconds, which would be consistent with the central apnea theory...

Regarding EPR, you were right. I checked, and my old CPAP device has EPR On, Full TIme, Level 3. Min pressure was 10.0, Max pressure 12.0.

I'm 33 and live in the US (California). I'm very comfortable making changes myself -- at this point I feel like aggressive experimentation is the only way forward

breathturn wrote: ↑

Fri Jan 05, 2024 3:59 pm

at this point I feel like aggressive experimentation is the only way forward

While I am pretty radical with my own experiments I don't often advise very radical ideas for others. I prefer to slow things down a bit with others and I don't suggest big or multiple changes unless there is a very obvious need..

breathturn wrote: ↑

Fri Jan 05, 2024 3:59 pm

Also, I had a more recent in-lab study (unfortunately, I don't have the data for that one, though I could maybe get my hands on it) where they said PAP was having trouble controlling my apnea.

Might be really interesting to know why they said that PAP was having trouble dealing with the apneas.
Makes me wonder if it was because of emergent centrals....that would go along with what we are seeing on your reports.

So.....my thoughts....I would like to see what happens if we
1....reduce or eliminate PS
2....reduce the pressure settings themselves....I don't think you need so much pressure to deal with the obstructive stuff and it won't help the centrals at all plus the pressures themselves could be a central trigger.
But I don't like making more than one change at a time because we don't know what change might have caused what result when we go making multiple changes.

You've been using a higher pressure for quite some time and that's what you are used to and if we go reducing the pressure itself very much then I suspect you might find it uncomfortable just because it is different from what you are used to. Been there and done that myself and it wasn't comfortable at all. I dealt with it because it wasn't unexpected but it was uncomfortable for a few nights.

So....let's try a small change first and that's reducing or eliminating PS and see what happens.
Cut the PS in half for one night and lets see what happens and how you do with it. Maybe change it to PS of 2.
Don't change the other pressure settings just yet.

I have a good friend that was having around 15 centrals per hour on average with a PS of 4 but with a PS of 3 she had only a random rare central pop up. She needed the PS because she also needed a minimum EPAP of 16 to deal with her obstructive apnea events.....16 cm without any exhale relief is a struggle for most people but the exhale relief triggered her centrals. I thought for sure we were going to need ASV for her but just a little drop in PS worked wonders for her.

Now I can't promise the same miracle for you but it wouldn't be totally impossible to see it happen.

At some point I would like for you to try a bit lower EPAP as well but again we will go slow with any reductions.
Don't want to mess with EPAP yet though....lets see what happens with just cutting PS in half.

Also...remember with any change in anything you really have to give it a few nights for your body to adjust to the new way of doing things. Unless we have a horribly horrible result...we keep the same settings for a few nights before changing more settings.

So for tonight....cut PS in half and that's the only change for right now. Report back tomorrow with results. I don't expect a miracle but sometimes I do get surprised like I did with my friend and a teeny tiny drop in PS from 4 to 3.

Pugsy wrote: ↑

Fri Jan 05, 2024 5:24 pm

While I am pretty radical with my own experiments I don't often advise very radical ideas for others. I prefer to slow things down a bit with others and I don't suggest big or multiple changes unless there is a very obvious need..

Sadly I've tried so many things with no results, that I feel I can now tolerate a lot and I'm willing to try pretty drastic changes, anything for data

I tried your suggestion of reducing PS to 2.0, leaving everything else unchanged (Max IPAP 21, Min EPAP 12). Here are the results:


Please let me know your thoughts. I didn't have any issues tolerating it in terms of breathing, but I did have a bit of gas/bloating/pain in the morning, so I think I was swallowing a bit of air.

The centrals did reduce in number.

But you are getting some aerophagia issues and that's from the higher pressures.
The reduction in PS effectively reduced the IPAP a little but not enough.

Let's try a reduction in pressure next....leave PS at 2 for now but depending on what we see with a reduction in EPAP/IPAP we may want to further reduce the PS but lets wait a bit.

I don't think you need 12 EPAP at all. Your pressure line looks more like a fixed pressure line despite it being able to go higher....it just doesn't want or need to go higher.
Let's drop EPAP minimum to 8 or 9 and leave PS at 2 and see how you do. It's a substantial drop from 12 so if too uncomfortable just drop the EPAP to 10. Let your own personal comfort be your guide. I need you to sleep and if you aren't comfortable you will have trouble falling asleep or staying asleep and that's not what we want.

Pugsy wrote: ↑

Sat Jan 06, 2024 6:27 pm

The centrals did reduce in number.

But you are getting some aerophagia issues and that's from the higher pressures.
The reduction in PS effectively reduced the IPAP a little but not enough.

Let's try a reduction in pressure next....leave PS at 2 for now but depending on what we see with a reduction in EPAP/IPAP we may want to further reduce the PS but lets wait a bit.

I don't think you need 12 EPAP at all. Your pressure line looks more like a fixed pressure line despite it being able to go higher....it just doesn't want or need to go higher.
Let's drop EPAP minimum to 8 or 9 and leave PS at 2 and see how you do. It's a substantial drop from 12 so if too uncomfortable just drop the EPAP to 10. Let your own personal comfort be your guide. I need you to sleep and if you aren't comfortable you will have trouble falling asleep or staying asleep and that's not what we want.

Thanks for the continued advice! I switched to min EPAP 8.0 for last night, and here's the results:



Overall this felt significantly more comfortable to me than before, and no aerophagia issues this time.

No further reduction in centrals to speak of with the reduction in pressure. Bummer...I had been hoping that maybe the higher pressures were triggering the centrals along with the PS but it doesn't appear that is the case.

Let's try another reduction in PS....cut it in half again so a 1 cm drop...leaving PS at 1. You can keep EPAP minimum at 8 but the machine probably still doesn't need quite the 8 cm since the machine doesn't really want to increase the pressure anyhow.

It does appear that PS is a factor in triggering your central apneas. That's a bummer as well because PS is kinda sweet but there is a small subset of people who have a problem using PS or exhale relief...or bilevel pressures.
It's the bilevel pressures that seem to cause the breathing instability that ends up causing centrals.
It is what it is. It does appear that you drew the short straw on that one.

How's your sleep quality??? Sleeping fairly soundly for the most part???

Pugsy wrote: ↑

Sun Jan 07, 2024 6:03 pm

No further reduction in centrals to speak of with the reduction in pressure. Bummer...I had been hoping that maybe the higher pressures were triggering the centrals along with the PS but it doesn't appear that is the case.

Let's try another reduction in PS....cut it in half again so a 1 cm drop...leaving PS at 1. You can keep EPAP minimum at 8 but the machine probably still doesn't need quite the 8 cm since the machine doesn't really want to increase the pressure anyhow.

It does appear that PS is a factor in triggering your central apneas. That's a bummer as well because PS is kinda sweet but there is a small subset of people who have a problem using PS or exhale relief...or bilevel pressures.
It's the bilevel pressures that seem to cause the breathing instability that ends up causing centrals.
It is what it is. It does appear that you drew the short straw on that one.

That's unfortunate, but I'm hopeful that I can tolerate low/no PS. We'll see

Pugsy wrote: ↑

Sun Jan 07, 2024 6:03 pm

How's your sleep quality??? Sleeping fairly soundly for the most part???

Unfortunately this has always been the problem for me: I can't consciously tell (because I don't remember them), but I in fact have a ton of small awakenings/movements (~100) during the night, whether I'm on PAP or not. Even looking at last night's video recordings, I have a lot of moments where I'm suddenly waking up / head twitching / other movement, even during times that OSCAR does not report any events. This is the mystery I've been dealing with for years . A lot of those awakenings do look like they could be breathing-related, but maybe they're not "major" enough to be picked up by the machine. This is why I mentioned the possibility of UARS / some type of PAP-resistant obstruction before.
All that said, I think the best we can do is stay the course with the adjustments for now, try to get the data looking as clean as possible, and see if that helps.

breathturn wrote: ↑

Sun Jan 07, 2024 6:34 pm

I think the best we can do is stay the course with the adjustments for now, try to get the data looking as clean as possible, and see if that helps.

That was my thought as well. Get things cleaned up as much as possible and see what happens.
I don't know that all your sleep problems are related to airway issues but for sure the number of centrals you were seeing was most likely messing with your sleep quality. So I figured that we could at least try to clean things up so at least you look good on paper and then give things a bit of time with you consistently using the cpap to at least give yourself a chance to see if cpap helps resolve your issues or not... at least give it a good trial. The way you were going for sure wasn't a good way.

I doubt the UARS thing....I would expect to see some RERA flagging if it was UARS and I just don't see it.
Lets hope you don't have UARS because historically more pressure is needed but with more pressure you will likely get more aerophagia issues and that will mess with your sleep quality as well....and we can't add in exhale relief to help with the aerophagia because exhale relief causes you to have a problem with central apneas popping up in numbers we don't like to see. Having an occasional central is normal and no big deal but it's not normal to have them in the numbers you were seeing. So I am not targeting 0.0 centrals as a goal. It's okay to have an occasional central.

You could just be having a truckload of spontaneous arousals as well. Not all arousals are airway related. That's a really tough problem because you have to try to figure out what is causing the spontaneous arousals before you can hope to reduce them. Spontaneous arousals mean no known cause for the arousal but they are NOT related to airway issues and cpap can't fix any problem if it isn't related to airway issues.

At any rate we still have a little bit of clean up work with the centrals shown (I would like to see central index to be less than 2 if at all possible) and then we can have you at least be able to tolerate the cpap therapy without major issues and give it a chance to try to help.

Making some progress though.

Pugsy wrote: ↑

Sun Jan 07, 2024 7:21 pm

You could just be having a truckload of spontaneous arousals as well. Not all arousals are airway related. That's a really tough problem because you have to try to figure out what is causing the spontaneous arousals before you can hope to reduce them. Spontaneous arousals mean no known cause for the arousal but they are NOT related to airway issues and cpap can't fix any problem if it isn't related to airway issues.

Yeah, for a while I was convinced that most of my arousals were not airway-related (because I had tried so much airway-related treatment, with zero improvement), but rather caused by something like a mild form of REM behavior disorder or similar. I tried some medications that are typically prescribed for RBD, but unfortunately they didn't help. Between that and improvement in my own monitoring, I'm now more convinced that airway issues are the main problem, hence giving PAP another shot, but it's definitely not a sure thing...

Anyways, I tried PS 1.0 last night, with the following results:



Seems like those CAs are stubborn

Yeah...those centrals are stubborn.
Plus given your history of frequent and numerous arousals we now have to add in learning how to figure out if the centrals are real asleep centrals or simply post arousal centrals. If you aren't asleep when flagged then they aren't real asleep centrals. When I see lots of centrals for myself I already know that the bulk of them are post arousal and don't mean much except I didn't sleep so great. When I have nights with considerable pain issues I always have lots of arousals and subsequent post arousal central flagging.

This is where you get a crash course in identifying real asleep centrals vs post arousal centrals (I like to call them false positive flags).

Do you know about the software SleepHQ? If not, get familiar with it because when you post a link to the report on SleepHQ it allows others to zoom in on the flow rate so we can see if there is evidence of arousal breathing just prior to the flagged event. If you will post last night's report on SleepHQ I can zoom in on the flow rate and look to make sure if those centrals are real asleep centrals or just post arousal centrals.

Pugsy wrote: ↑

Mon Jan 08, 2024 5:51 pm

Yeah...those centrals are stubborn.
Plus given your history of frequent and numerous arousals we now have to add in learning how to figure out if the centrals are real asleep centrals or simply post arousal centrals. If you aren't asleep when flagged then they aren't real asleep centrals. When I see lots of centrals for myself I already know that the bulk of them are post arousal and don't mean much except I didn't sleep so great. When I have nights with considerable pain issues I always have lots of arousals and subsequent post arousal central flagging.

This is where you get a crash course in identifying real asleep centrals vs post arousal centrals (I like to call them false positive flags).

Maybe a silly question, but what causes post-arousal centrals? I would have expected that I would be breathing normally post-arousal?

Pugsy wrote: ↑

Mon Jan 08, 2024 5:51 pm

Do you know about the software SleepHQ? If not, get familiar with it because when you post a link to the report on SleepHQ it allows others to zoom in on the flow rate so we can see if there is evidence of arousal breathing just prior to the flagged event. If you will post last night's report on SleepHQ I can zoom in on the flow rate and look to make sure if those centrals are real asleep centrals or just post arousal centrals.

Nope, but I do now
Hopefully I got this right, let me know if you need anything else: https://sleephq.com/public/a6fbf8a5-de2 ... e6fc7ef923