Treating flow limitation causes more central apneas?

[knarf]

If the solution to flow limitation is to use BiPAP, but the solution to central apneas is to turn off EPR, what if I have both flow limitation and CA?
I'm a newbie at this stuff so please correct me if I'm misguided in any way

I've noticed that my CA events are incredibly long (almost a minute), and I tried ramping down my EPR by a bit to resolve it, which recently seems to have somewhat worked. But I'm concerned that this would cause greater flow limitation, which I think I might have based on looking at my charts? Again please correct me if I'm wrong. Also I'm not sure if this is unrelated but my tidal volume also seems to be lower when I ramp down my EPR.

So the question is, for the more experienced folks out there, does a tension exist between treating CA and treating flow limitation?
If I pick one, will the other likely suffer? And from your experience, which is more important to treat?
Have any of you felt better treating your central apneas while ignoring flow limitation? And what about vice versa?

And finally, what would you recommend for me?

I've linked some OSCAR charts below: (looks like there's no quota to upload images)
https://i.imgur.com/i8pRIvb.png
https://i.imgur.com/rzIqurg.png
https://i.imgur.com/zQD79LK.png
^Last one is 2 charts merged into 1

And here are my sleep studies:
2018 Initial
https://www.scribd.com/document/6681411 ... HnpBfYIESF

2018 Titration
https://www.scribd.com/document/6681419 ... dukjDQlcBk

2023 Initial
https://www.scribd.com/document/6681419 ... sjgTF3wzJW

2023 Titration
https://www.scribd.com/document/6681419 ... tXsVRlCvsj

(Looks like using CPAP also increased my central apneas during these studies)
Thanks everyone!

[palerider]

Increase you min pressure, and if the insignificant centrals are bothering you, then reduce EPR.

'course, reducing EPR has the effect of raising your minimum pressure.

[lazarus]

If the solution to flow limitation is to use BiPAP,

Bilevel is not the only form of PAP that can stabilize the airway. Technically, inspiratory flow limitations are fixed by increasing breathe-in pressure. So with bilevel, one would increase IPAP; with CPAP, one would increase overall pressure; and with APAP, raising minimum pressure to within a cm or two of what is needed to prevent apnea can also keep pressure high enough to keep the airway more stable as you breathe in.

but the solution to central apneas is to turn off EPR

This can help some but is by no means a universal truism. It is something to try, nothing more.

what if I have both flow limitation and CA?

This would not be rare. Most everyone with OSA occasionally experiences both. The self-titrators among us tweak our pressure(s) and settings to minimize both. It is not a contradiction that the state of one's airway can affect blood chemistry and that blood chemistry can have an effect on the physical airway. It is one big interrelated system that just has different sorts of sensitivities when comparing one patient to another.

If I pick one, will the other likely suffer?

No. Treating one can help the other. Especially will keeping the airway stable help everything. If that can't be done over the long-term with CPAP or APAP, then more specialized modalities may need to be explored.

which is more important to treat?

Stabilize the airway first and primarily, but do so in a way that won't further destabilize breathing in any way long-term. Ignore any short-term occasional pauses in breathing, especially the ones that are merely symptoms, or manifestations, of restless sleep. A flow limitation is generally a problem to address (which is why many forms of IFL will cause increases in APAP pressure) whereas a central is a symptom of something else (which is why home-treatment machines now generally ignore open-airway pauses).

Even perfectly healthy humans with no OSA at all can be made to have pauses in their breathing if you put them on bilevel with enough distance between IPAP and EPAP. But leave it in place and many will adjust to it as the body and nervous system gets used to the lessening of their work of breathing. And similarly, many without OSA have breathing pauses when at higher altitudes. These phenomena are not manifestations of disease states. They are natural reactions to adjusting to changes in circumstances.

Likewise, using PAP is a change in circumstance that can involve some harmless pauses in breathing. That should not distract from the primary goal of PAP--stabilizing the airway without further disturbing sleep. It is only when centrals are proved to disturb sleep that (in the context of sleep medicine) they start to take on their own significance for treatment-pressure decisions.

As I underatand it.

[knarf]

Increase you min pressure, and if the insignificant centrals are bothering you, then reduce EPR.

'course, reducing EPR has the effect of raising your minimum pressure.

Hmm, could you elaborate on why you believe my central events are insignificant? To me it seems like 50 seconds is a long time, and other people don't really have CA events for that long right? I guess I'm looking for an explanation for why I shouldn't be concerned about my very long CA events

Also I fixed the links to all my in-clinic sleep studies. Thanks!

[knarf]

Stabilize the airway first and primarily, but do so in a way that won't further destabilize breathing in any way long-term.

I don't quite understand, could you elaborate on what you mean by "further destabilize breathing in the long term"? And how would I be able to make sure this doesn't happen?

And similarly, many without OSA have breathing pauses when at higher altitudes.

Sorry just to check my understanding, do you instead mean to say that many people without OSA will have breathing pauses at lower altitudes (instead of higher altitudes)?
I'm assuming that lower altitudes will mimic CPAP, which might give them central apneas? Or am I misunderstanding something

Overall could I say that for people that have sleep apnea, their bodies have adapted to sleeping with a high CO2 level, so when CPAP is introduced their CO2 levels easily fall below the threshold, which makes their body decide breathing is not necessary? Is that what causes the central apnea, or am I still misunderstanding what's happening?

Likewise, using PAP is a change in circumstance that can involve some harmless pauses in breathing.

Hmm I guess I have a hard time being reassured because 50 seconds seems like a lot. Have other people gotten CA events close to that?

It is only when centrals are proved to disturb sleep that (in the context of sleep medicine) they start to take on their own significance for treatment-pressure decisions.

Ok final question, in what conditions do CA events proven to disturb sleep? (Also not sure what that would mean)

Also I fixed the links to all my in-lab sleep studies.
Thanks for the detailed reply!

[palerider]

Increase you min pressure, and if the insignificant centrals are bothering you, then reduce EPR.

'course, reducing EPR has the effect of raising your minimum pressure.

Hmm, could you elaborate on why you believe my central events are insignificant? To me it seems like 50 seconds is a long time, and other people don't really have CA events for that long right? I guess I'm looking for an explanation for why I shouldn't be concerned about my very long CA events

Also I fixed the links to all my in-clinic sleep studies. Thanks!

because they're not happening very often, it's not disturbing your sleep.

[palerider]

Hmm I guess I have a hard time being reassured because 50 seconds seems like a lot. Have other people gotten CA events close to that?

SEEMS, but your body simply did not want to breathe, did not *need* to breathe, because your CO₂ levels were low, when they built up, you started breathing again.

[knarf]

SEEMS, but your body simply did not want to breathe, did not *need* to breathe, because your CO₂ levels were low, when they built up, you started breathing again.

I know the machine uses some algorithm involving pulses of air to determine whether the event is a CA or an OA, but I'm wondering if there's any chance the algorithm could have made a mistake? How do I reassure myself that I didn't just have a 50 second obstructive episode, which I assume would very much need to be dealt with?

[ozij]

Because the algorithm was tested before the machine was given FDA approval.

It may tag central apneas as obstructives, but it does not tag obstructives as centrals. In Auto mode it responds to them.

Suppose 90 ignorant people gave one reply to yuor poll, and 10 knowledgeable people gave another reply - would you be better off?

This is your third thread on what is basically the same issue: You concern with the length of your central apneas.

It would be helpful to those who want help you if you were to stick to one thread.

lazarus wrote: ↑Tue Sep 05, 2023 2:56
And similarly, many without OSA have breathing pauses when at higher altitudes.

Sorry just to check my understanding, do you instead mean to say that many people without OSA will have breathing pauses at lower altitudes (instead of higher altitudes)?
I'm assuming that lower altitudes will mimic CPAP, which might give them central apneas? Or am I misunderstanding something

You are misunderstanding. CPAP is Continuous Positive Air Pressure - air pressure that is by definition higher than the ambient pressure.

Central Sleep Apnea at High Altitude

[knarf]

because they're not happening very often, it's not disturbing your sleep.

Yea it's not very often, but I did notice that on Aug31st (when my pressure was significantly higher at 10.2), I had a lot of central apnea events. I felt so awful on that day I'm almost afraid to try that pressure again, although I recognize it might be some coincidence.

Here are some charts of that night:
https://i.imgur.com/OP0Mc8C.png
https://i.imgur.com/LtpPWyK.png
https://i.imgur.com/Gf6uqjE.png
https://i.imgur.com/EpxsZTT.png
https://i.imgur.com/huH71bK.png

It seems like, based on the shape of my respiration, that my flow limitations were still not fixed at 10.2 of pressure. (Again please correct me if I'm wrong)
Based on what you two are recommending, if I understand correctly, I should try bumping up the pressure right?
But then if I do that, how can I avoid a massive spike in CA events?

I guess I still don't fully understand how flow limitations and CA events can affect one another
If I were to speculate then I would say, OK maybe my flow limitations lessened in severity on Aug31st? (Although I didn't notice any changes on the graph)
And because my flow limitations lessened, my body was getting enough oxygen, therefore it doesn't need to breathe as often, therefore increasing CA events?
Could that be what happened?

But if that's the case, then how come I felt so horrible waking up the day after Aug31st? If my flow limitations improved why did I feel worse?

And on the other hand, if my flow limitations actually did not improve, then what could be triggering my increasing in CA events that night?
I'm very confused about all of this. Anyways, would this new data point change your assessment of my situation?
Thanks!

[ozij]

Please post the full night from which those snippets were taken.

[knarf]

It may tag central apneas as obstructives, but it does not tag obstructives as centrals.

Ok this is good to know actually, thanks

Suppose 90 ignorant people gave one reply to yuor poll, and 10 knowledgeable people gave another reply - would you be better off?

This is your third thread on what is basically the same issue: You concern with the length of your central apneas.

My bad for posting so many, but my previous posts either got little attention, or fizzled out despite me still having unanswered questions.
So I did some more reading about these topics, and then went back to the drawing board to see if I could come up with an actual question based on the new information I read, and that's how I came up with this post. I did a poll because I was not sure if people were going to reply, or if I would get nothing, like the 2nd thread I posted. So I figured if people don't respond, they might at least cast a vote. If I get even a few votes saying I'm misguided, then I'll know something is wrong. Overall I'm hoping this time I asked a more specific question. Or maybe not, as I'm still definitely a beginner. Either way I'm happy this thread got more replies

You are misunderstanding. CPAP is Continuous Positive Air Pressure - air pressure that is by definition higher than the ambient pressure.

Yep I understand that CPAP is higher than ambient temperature. I was just curious why lazarus mentioned higher vs lower altitudes. Although I suppose my guess did not really make sense, considering the laws of physics.
Oh well, either way I have new data, new questions and I would always love some help

[lazarus]

I don't quite understand, could you elaborate

Make small moves over time that lower overall AHI and improve sleep-quality. Work for long-term improvement with the tools you have. That's generally better than assuming one apparent 50-second pause is a reason to consider ASV. Because ASV would be the only tool that is available that would beat a pause into submission.

The altitude example was just to explain that not all pauses are pathological.

The thing people often fail to understand is that airway narrowing in a mini-strangulation that stresses the body, so it is an actual meaningful event that very often tends to disturb sleep. Flow-limitations therefore matter medically all on their own. On the other hand, a central is either a mere symptom of some other serious medical problem, or it is something to be ignored (if it isn't destroying sleep quality, as established by a sleep doc interpreting an in-lab study).

You can always use a breathing concern as a reasonable argument for a full cardiovascular workup, if you want. But if there is nothing found by a doc to be treated medically or surgically, then occasional pauses are often just, uh, occasional pauses. And feeling bad in the morning can be because restless sleep showed up in your AHI, not because centrals caused restless sleep.

I had a lot of scored centrals and mixed events in my in-lab diagnostic and titration. But my slowly, methodically, scientifically tweaking APAP pressures to get AHI as low as reasonably possible allowed my systems to heal enough for those events, after many months of optimized PAP, to go away.

I still will have a few open-airway apneas show up after a night of especially restless sleep, but I don't let that worry me.

YMMV.

But slow moves, over time. Let weeks go by. Go by averages, not one night. Your body has to get used to the settings you choose and settle into them.

Ozij's wisdom helped me a lot back when I was starting out. My best advice to anyone would be to listen closely to her experienced thoughts and observations.

I didn't participate in the poll.

[knarf]

Please post the full night from which those snippets were taken.

The full night is here: https://i.imgur.com/bihYXaO.png
Thanks!

[ozij]

Ozij's wisdom helped me a lot back when I was starting out. My best advice to anyone would be to listen closely to her experienced thoughts and observations.

@knarf :In case you're wondering, that was actually many years, and some of Lazarus' identities ago....
@Lazarus - one wouldn't know, looking at your username, how knowledgeable, thoughtful and experienced you are after all those years. Though reading your posts makes it very evident..

I didn't participate in the poll.

Neither did I.

But slow moves, over time. Let weeks go by. Go by averages, not one night. Your body has to get used to the settings you choose and settle into them.

Indeed,

Please post the full night from which those snippets were taken.

The full night is here: https://i.imgur.com/bihYXaO.png
Thanks!

Your flow limitations are negligible, you central apneas numerically are nothing to worry about. Which is not say you're sleeping well

SEEMS, but your body simply did not want to breathe, did not *need* to breathe, because your CO₂ levels were low, when they built up, you started breathing again.

By making the blow off of CO2 easier, EPR may be causing the unstable breathing that is visible in you chart, and those long breathing pauses.
The first thing I'd do, if these were my results would be to use the machine as it was used in the sleep study:
A fixed pressure of 10, no EPR.
If you find that change too uncomfortable, reduce the EPR gradually, first to 2 then to 1 then to 0. Give yourself time to get used to each change.
As Lazarus said, slow moves, over time, it might take weeks.