CPAP Cause Central Apneas?

Hi!

Just wondering if CPAP can cause Central Apneas??

I took a nap with my CPAP today and noticed what I felt like was a central apnea as I was drifting off.

If cpap CAN indeed cause central apnea then I have a few questions

1) Why and how? (just curious)
2) Does your breathing system eventually adapt and you stop having central apneas on cpap? If so how long usually?
3) Are Central apneas more likely to occur on back then on side??

thank you!
Tyler. (Guest)

Also one more question,

If one is having central apnea events, then what is the best setting to be using on ones cpap machine?

(I have a Respironics Auto-M with A-flex)

Does Central/Mixed Apnea respond better to a-flex, c-flex, or normal cpap?

I've noticed that so far I have had a really tough time with the a-flex, sometimes I feel like it is sucking the air out of me. For instance If I take a longer breath then the one before, it automatically pulls back on the pressure and I have a split second feeling of not getting any air. I guess I just have to learn to keep my breathing steady and even when using a-flex.

any thoughts?

Before I got on CPAP therapy, I would find myself waking up in the middle of the night and find myself NOT breathing! It was as if I were frozen there. My heart would start beating rapidily and then all of a sudden...I would start breathing again. You should know that it had nothing to do with my tongue blocking my airway...no! no! no! Well, now on CPAP when I am first falling off to sleep, I once again am noticing that I literally am just stopping breathing but the machine just steps in. Am I experiencing more of these on CPAP? I don't know yet. Good question.

Guest, what you're describing sounds very much like "sleep onset centrals" -- normal. Nothing to worry about. Normal...not caused by cpap:

I'm going by what StillAnotherGuest (a sleep lab manager and RPSGT, RRT) has written:

page 2 of this thread:
viewtopic.php?t=14225

"1. Sleep-onset centrals (if that's what they truly are) are generally harmless;"

I think there is more they don't know about the brain than what they know. As for central apnea, I really don't think they know the exact cause of them. If they do it is only theory, one theory is the signal gets interrupted coming from the brain. Another says it is plaques found on the brain stem. Yet when those that have CSR have a high-res MRI of the brain stem they find no plaques.

Of course some of us also believe that central apnea is a natural occurring anomaly. Our body has more checks and balances then we give it credit for. Look at your brain it has 4ea redundant arteries feeding it with its blood supply. Why? because well without your brain you are pretty much dead. We all need a little bit of CO2 retention, exhaust too much out and I believe the body will respond by holding back with breathing until that level comes back up to desired levels, one of its checks and balances (is my theory).

Just like the limit switch on your garage door opener to stop it when it gets to the top or bottom, your body has limit switches within its chemoreceptors. Sure those switches can get out of adjustment and/or malfunction then you have all kinds of problems, but for the most part it does a pretty darn good job.

If you look at how they now treat Complex Sleep Disordered Breathing (CSDB) they do it by carefully controlling CO2 levels using known/specified masks with additional dead space along with airflow volume control. Combined these methods stabilize your breathing and those central events go away on their own. Sometimes when you need the body to respond a certain way you need to fake it out so that it responds appropriately. And that is pretty much what they accomplished with the AdaptSV therapies. Resmed has their preferred way and Respironics theirs. The book is still out on which is best, but you can expect to see improvements to both as time passes.

Below are your chemoreceptors that control respiration,

and some of your limit switches (in my theory)

My only comment is that I continue to be grateful that we have members such as rested gal and Snoredog

I can't comment on the prevalance (and cause) of this in the general population, but I can comment on what happened to me:

- No central's seen on overnight PSG
- During titration (separate night), 2 central's seen right when i was just falling asleep (titration using AutoPAP), which I also felt because I jerked wide awake and looked at the clock (which correlated with sleep doc's charts).

-> Sleep doc said the central's could be due to the pressure of the CPAP (but none were noted once I was actually asleep)

-> She wasn't sure what pressure to prescribe, too low=not therapeutic; too high=may induce central.. so she set me at 7 (which was on the "low" end).

- During first week at home with straight CPAP (set at 7), no jerking awake (central's?) that i can recall.

- Increased to 10 for a while (7 wasn't helping)... started mouth leaking. So I started taping. This helped significantly for the obstructive apneas, but on certain nights I could FEEL that the pressure was too high, because as I was just almost falling asleep I could feel myself jerking awake again (possible central?), and it was accompanied by a funny light headed feeling as well.. so I would decrease by 0.5cm, and that funny feeling would disappear, no more jerking awake, and normal sleep.. This kept happening until I got to 8.5, and now everything's fine. (I don't have a data capable machine so I can't correlate my subjective feelings with any real data).

So in summary, at least for me, I guess SWS's conjecture might hold true (taken from RG's link above):

SWS wrote:However, there may be a few of us for whom the application of PAP machine pressure just may skew that short-term homeostatic adjustment process on a transitional-only basis (versus the sustained CSDB/CompSAS effect mentioned below). If there is any grain of truth to that conjecture, then these rare patients might show a comparative increase of SDB events immediately after the application (or mid-session reapplication) of pressure---if their pressure-skewed homeostatic maladjustment is merely transitional. Unfortunately that's conjecture only, and not established scientific fact.

Echo, you quoted one of the most intelligent people I've ever met. -SWS was responsible for helping me get my autopap treatment going right years ago. A fantastic mind. Thanks for quoting him!

Glad you got your treatment working well for you.

Thanks RG, couldn't have done it without you and all the other wise people here on the forum

I'm still waiting for the my PB 420E (shipping problems!!!!)...

Was SWS the one that got you the 3-night PSG study when setting up his new lab? I loved reading your report of the whole thing!

Nope. -SWS, like me, has no connection with the sleep or medical fields at all.

The person who got me the 3 night sleep study was StillAnotherGuest. SAG is the manager of a top sleep lab. The wonders of the internet!!!

I imagine SAG's in secluded mourning right now - his beloved Mets lost.

Got a copy of the actual reports from my sleep studies for the first time today - this is a timely thread.

Evidently in my first study, the number of central events was minimal. During my titrated study, the sleep doc noted that my obstructive events went away but I did have a number of central events w/CPAP.

Wasn't sure if that was bizarre coincidence or what. Nothing I'll lose sleep over, but I thought it was interesting that he pointed that out in the report. May or may not be related, but my prescribed pressure was a little lower than my final titration during the study. He noted in the report that I did as well at a lower level as I did at the final level.