Does CPAP Cause Central Apneas?

Continuing on the current interest in central apnea, I thought this video was clear and easy to grasp

Does using CPAP cause Central Sleep Apneas? Is there such a thing as a CPAP induced Central Sleep Apnea?
https://www.youtube.com/watch?v=1OQFESwNXm0

Yes and no - it's possible that in a few people raising their pressures to a high level relative to others may provoke some centrals. But just using Cpap normally does not 'cause' centrals in most people.

Of course.
Jason's video is very good and it shows SWJ central very well using SleepyHead flow rate as example.

Not everyone will get pressure induced centrals...I think last I read maybe 10 to 15 % of the people who start cpap will get them.
Jason mentions the pressure being "too high" as a cause...it can be any pressure that is "too high" for that particular person. I have seen people develop centrals at pressures as low as 5 or 6 and that can create a significant problem because they might be needing higher pressures to deal with the obstructive apnea events. Talk about caught between a rock and a hard place.
They have no choice but to move on to the higher end machine designed to treat both central and obstructive sleep apnea. Usually the ASV type of machine but in some situations the doctor will use a different bilevel machine with a fixed back up rate instead of the auto back up rate that the ASV used.

Complex sleep apnea...ResMed has a good video explaining and talks about how ASV helps resolve the issue.
https://www.youtube.com/watch?v=CU-XTcf ... e=youtu.be

For some people who develop complex sleep apnea because of any cpap pressure with some time the body will learn to adjust and not go into the unstable breathing pattern that causes the centrals. So that's why we say that sometimes the centrals will go away on their own. For some people they do but for some people they don't or it takes way too long and in the meantime their sleep is totally trashed from way too many centrals. Centrals will cause arousals and sleep disturbances just like obstructive apneas can disrupt sleep. So when do we elect to give it time???? That depends of the severity of the centrals and it's more than just how many but also duration and are they disrupting sleep. So several factors besides just the presence of a higher than wanted central count.

SWJ centrals (even if technically a central by definition which is cessation of breathing for 10 seconds or longer) don't count. They aren't "real" in the sense of meeting criteria to cause about a person to earn the complex sleep apnea diagnosis. Awake stuff...anything...doesn't count no matter how ugly it might be. As hard as it is to do we have to mentally removed any SWJ stuff from our evaluations of the therapy. This is sleep apnea...not awake apnea and you gotta be asleep for them to matter.

So remember...it can be any pressure not just a high pressure and most people can handle the pressures (even quite high) without going into the unstable breathing pattern that triggers centrals. I see pressures over 20 quite over on my bilevel machine but I don't get the unstable breathing and I don't have more than an occasional central. If you have to use higher pressures...remember only 10 to 15% of the people using cpap will get those pressure triggered centrals so you have a greater chance that you won't have a problem with centrals.

Also remember...it's normal to have a few centrals during the night anyway. There's a central caused by sleep stage transition....we call them sleep onset centrals and it's normal to have them. They aren't usually a problem unless they are extremely numerous and/or they keep bouncing a person out of sleep so that they totally trash sleep quality.
So don't panic if you see a few centrals here and there...they could be real and maybe a sleep onset...they could be SWJ turning over in bed central...they could be totally awake fighting insomnia centrals with lots of tossing and turning and be real ugly but if you are awake...they don't count.

Duration is important...by definition a central is cessation of breathing that last 10 seconds or more. Hold your breath for 15 seconds...that's pretty much a central that lasts 15 seconds. It's not going to cause much of a problem in terms of oxygen levels unless you start doing it for a much longer duration and doing it for several minutes in a row...
A random short lived central isn't going to cause a drop in oxygen unless you have some serious lung issues going on and if you did you would very likely already know about it.

So don't panic if you see a few centrals...we aren't going to ignore them but we will watch them and see what happens and try to figure out if they are real or not or SWJ centrals.

How many is too many? Well the medical community has to have some sort of guideline so they setup the line in the sand at 5. No mention as to duration which is important but that's what we live with.
If you are seeing borderline 5 centrals per hour that you can't explain away as SWJ...probably should at least talk to your doctor about things and see how he wants to proceed. He might want to give it time and see if they will reduce on their own (because for some people they will) or if your sleep is totally trashed he might not wait. He's going to take into account not only the hourly average but duration and affect on sleep quality and maybe even oxygen levels if they are very long. 10 seconds isn't going to cause a drop in oxygen though unless someone has some really bad lungs.

Now if you are seeing central hourly averages in the double digits...I don't know if there is enough time for those to go away on their own.
Typically the "go away on their own" will take weeks and months...like 6 months to a year. Someone with a borderline worrisome central number will have a better chance with the "give it time" thing than someone with double digit hourly central averages.

As always...if you are concerned about anything on your software reports...see your doctor.
Don't panic if you see a few centrals and don't panic if you see a large number...they can be dealt with fairly easily.
ASV may or may not be the way they are dealt with. Your doctor makes that determination based on medical history and what is going on.

So the question "does cpap cause centrals"....yes in some people but only a relatively small number of people who start cpap therapy. It's not nearly as common as people might think.

Now also remember...this relates to people who didn't have centrals on the diagnostic sleep study and get them with cpap therapy.

Pugsy wrote:. . . ASV may or may not be the way they are dealt with. Your doctor makes that determination based on medical history and what is going on. . . .

+1

I believe that the whole concern about "too high of a pressure causes CA" is basically malarkey about 99.9% of the time; it is mostly a scare tactic used by some unscrupulous RTs as a way to keep people from taking charge of their own therapy.

In my case, I had a LOT of central apneas and mixed apneas at first myself. It took a few months, but they eventually resolved once my body/brain got used to PAP. I needed bilevel at first, but now I do just fine with APAP with a few cm of pressure relief, which for me, feels very close to bilevel.

Having centrals with PAP isn't necessarily a problem. Even having a lot of centrals that never go away after months of effective treatment of the obstructives is only really a problem when it disturbs sleep or causes other problems with blood gas. What many forget, I believe, is that obstructives are damaging in and of themselves. Always. They are to be attacked. Centrals are a different beast. Centrals are generally no big deal, and when they are it is because they are a symptom of some other problem that needs to be looked into. And an initial increase in centrals is a fairly common thing until the body adapts to PAP, so they aren't a reason to panic. Just something to note and watch at first.

So when initiation of PAP "causes" centrals, the first step is often just to make the obstructives go away with CPAP in order to see if the body fixes breathing further on its own. It is only when that does not happen and the centrals create some issue with sleep or with something else that they become an issue to a doc that needs to be dealt with instead of ignored, or at least looked into. A good doc's judgment on that is worth taking into full consideration instead of just demanding ASV right away, in my opinion. Too many here think of ASV as a better PAP machine, I believe, when that isn't exactly what it is. It is a special machine for special circumstances. If you need one, great. But if you don't, they can be a bit more of a hassle than a non-ASV PAP machine.

PAP use may UNMASK a CA problem. True. And for a time, an effective pressure may cause someone with very bad OSA to have some centrals as the body adjusts. But the true pure "mixed"/"complex" problem persisting is, in my opinion, VERY rare. Most can eventually adjust to non-ASV PAP. When that is not the case, then ASV is a wonderful tool for helping such people. ASV can even be helpful to people off-label in dealing with plain-vanilla OSA for a select few, I understand. But that does NOT mean that every person with a few centrals should demand to be rushed onto ASV.

Hey, just me.

jnk... wrote:Most can eventually adjust to non-ASV PAP. When that is not the case, then ASV is a wonderful tool for helping such people. ASV can even be helpful to people off-label in dealing with plain-vanilla OSA for a select few, I understand. But that does NOT mean that every person with a few centrals should demand to be rushed onto ASV.

Totally agree with you.

And people need to understand that having 2 centrals in 4 1/2 hours of sleep doesn't constitute anything anywhere near a central apnea diagnosis on top of the OSA diagnosis. Especially if those 2 centrals are 20 and 25 second duration even if they are the real deal and not SWJ centrals.
I think a good many of the centrals that newbies see are SWJ centrals because they aren't yet sleeping so soundly with cpap. Awake or semi awake stuff doesn't count in the evaluation process but they get all in a panic and someone comes along and scares the hell out of them for no reason at all.

As someone who is using ASV off label just because I am crazy enough to do it....and I got the machine cheap enough that I could do it...doesn't hurt to use one and it has one advantage that I in particular like.

Most people can't afford one even if they really need one and have to rely on insurance and go through the hurdles to justify the expense.
I have often thought that those hurdles are set because sometimes with time the centrals go away and then the insurance company can say "see...you don't have a problem" and thus they don't have to fork out the big bucks.

That's true too. It is a shame when someone could truly benefit from ASV and has a hassle getting it.

In my case, I believe that the years of untreated OSA had thrown my receptors way off. Once I was on PAP, my waking breathing went through a lot of changes too, not just sleep breathing. It felt as if I had many centrals during the course of the day while I was awake, as in the classic "I keep forgetting to breathe" that is mentioned here from time to time. I got light-headed during the day. I had many nights of terrible AHI for a good while, but as long as I saw progress over time over the weeks with my trending data, I simply stayed the course.

Now I'm not saying that's the way everyone should go. Maybe my journey would have been smoother with ASV. But I find the whole scare-tactic thing about CPAP "causing" centrals a little over the top. In this era in which it has been proved that a few extra cm of pressure, whether added to titration or provided by APAP, is only rarely an issue for anyone, the entire concept of "CPAP causing centrals," even if technically true in some rare instances, still makes the hair stand up on the back of my neck from having heard it from so many newbies told that by pros who just didn't want a patient to touch the clinicians menu.

That's why, although technically I can see why the answer may be yes, my reflex is to answer the question "Does CPAP Cause Central Apneas?" with a resounding "NO!" It may unmask them. It may cause some pauses in breathing until the body adjusts. But when "centrals" show up, or increase, around the same time that PAP is initiated, it is the correction of one serious problem that either allows another minor problem (or nonproblem) or unmasks a symptom that should be investigated. At least, that's the way I think of it, which is based, at least partly, on how I've heard a few researchers express their views on it.

But I tend to overreact sometimes.

jnk... wrote:That's why, although technically I can see why the answer may be yes, my reflex is to answer the question "Does CPAP Cause Central Apneas?" with a resounding "NO!" It may unmask them. It may cause pauses in breathing until the body adjusts

The answer is "yes" but there should be a big BUT along with the yes.

I have seen people have a truckload of centrals with cpap pressure as little as 6 (and none on the diagnostic study) and 6 doesn't even come close to treating the obstructive apnea. Those people just need to go directly to ASV. Having 20 or more centrals per hour and not even dealing with the Obstructive stuff simply isn't a good option. They shouldn't have to wait to "give it time" especially when there is no guarantee that giving it time will work in their situation.
There is a time and place where the best option is simply to go directly to ASV...no sense in making crappy sleep (from OSA) worse by adding in a truckload of centrals too. Pretty much guarantees horrible sleep and a substantial chance of oxygen level issues with that many events of any kind.
In this day and time there's just no reason to be miserable and cpap should be fixing problems and not causing more problems.

It's like everything else about cpap...has a big huge YMMV sticker on it and we just can't give simple yes and not answers most of the time....they all have big "BUTS" at the end of yes or no.

You got lucky in that your body adjusted and the centrals went away BUT (that big but) not everyone is that lucky. Each person needs to be evaluated on a case by case basis when centrals are more than we like to see.

BUT....there's that but again....some people here are the forum are too quick to go down the "you need ASV or other bilevel with back up rate" road when people are having a few centrals that may or may not be real. And an AHI of less than 1.0 that is all central certainly doesn't warrant ASV unless those centrals are massively hugely long and if they are hugely long there's some other issues going on that needs to be addressed first.
Scaring the hell out of newbies and you know how protective I am of newbies. This therapy is hard enough without scaring people and adding stress when there simply isn't a need.

Pugsy wrote: . . . I have seen people have a truckload of centrals with cpap pressure as little as 6 (and none on the diagnostic study) and 6 doesn't even come close to treating the obstructive apnea. Those people just need to go directly to ASV. Having 20 or more centrals per hour and not even dealing with the Obstructive stuff simply isn't a good option. They shouldn't have to wait to "give it time" especially when there is no guarantee that giving it time will work in their situation.
There is a time and place where the best option is simply to go directly to ASV...no sense in making crappy sleep (from OSA) worse by adding in a truckload of centrals too. Pretty much guarantees horrible sleep and a substantial chance of oxygen level issues with that many events of any kind.
In this day and time there's just no reason to be miserable and cpap should be fixing problems and not causing more problems. . . .

Thanks, Pugsy. That helps adjust my attitude. And I need that from time to time.

I REEEAAAAALLLY appreciate your being here.

In support of Pugsy's points:

" . . . CompSAS [comlex sleep apnea syndrome] resolves in only about one third to two thirds of patients treated with CPAP . . . ASV is superior to CPAP in both acute and long-term control of SDB. Further research should focus on expanding clinical and physiological evaluation of patients with CompSAS to better define the subset of patients that are unlikely to benefit from CPAP and who require more advanced forms of PAP therapy. . . ." -- SLEEP, Vol. 37, No. 5, 2014 https://academic.oup.com/sleep/article- ... .5.927.pdf

When my wife first started she had 8 to 10 central apneas per hour with her pressure at 10 - 12 cm H2O. Within a month, the number of centrals went from that to under 2. Every time we would raise the pressure, the number of centrals would go up to 8 to 10, then reduce to under 2. We are slowly raising her pressure to the targeted pressue of 20 cm H20. I will raise her pressure to 18 today, and I expect her centrals to go up for a few days, then drop again. When I first started treatment, I was having three or 4 centrals every hour. Now, I usually have from 1 to 4 per night.

jnk... wrote:In support of Pugsy's points:

Thanks jnk. One third is a decent percentage that could resolve on their own and it's certainly worth giving it a shot unless there are some unique circumstances happening to complicate things even more.
I think that the chances of "time fixing things" are much greater if the number of centrals is on the lower side...like Okie biPap and his wife.
Slimmer chances if the number of centrals is up in the high teens and/or more. Like just how much "time" do we need to bring a central index from 30 down to less than 5.

Doctors have to look at the big picture (duration, O2 levels, sleep quality in general) and make a decision if the situation warrants the "time" test or jump right in with ASV.
Not only are ASV machines expensive they come with their own rather unique potential issues...that big burst of air needed to breathe for a person when there is a central can cause arousals and/or aerophagia problems.

Also what we really haven't discussed is sometimes there is a line where so and so pressure may trigger enough centrals to warrant concern and may 1 cm below that line there are not enough centrals to warrant more than a wait and see approach.
As long as the 1 cm below the line pressure takes care of the obstructive stuff then there's no need to go to the high dollar machine.
I have seen it many times...that invisible line where as long as the patient stays below the line their OSA is well treated and centrals don't rear their ugly head in numbers high enough to warrant concern.

So often centrals can be easily managed by "time" or prudent use of pressure settings. Might as well try the "easy" way first because there's a decent chance it will work.
We aren't ignoring them...we are going about the business of treating the OSA stuff and keeping one eye on the centrals in the process.
Fix what is known to be needing fixing and then see what's left that we can't fix and go from there.

From my point of view, IF it is long-term untreated severe OSA that has caused the chemo-receptor-distorted dysregulated breathing that is showing up as central events in the person, then treatment of that cause is likely to give the body what it needs to be able to heal what is presenting as unmasked CSA or as CompSAS; whereas, if other issues (heart/lung/drug/altitude/etc) are contributing to the breathing issues, simply making the airway patent during sleep is unlikely to be enough.

xxyzx wrote: . . . most of the problems are caused by normal people . . .

https://www.youtube.com/watch?v=inqdiNVzQcc

xxyzx wrote: with a 2/3 chance of making things worse why risk it at all ?

dont risk it and you get better treatment

Because you don't get you choose your machine....your doctor and your insurance company does that for you unless you want to buy one yourself.
33% chance of success trying something is better than doing nothing...doing nothing guarantees failure and OSA going untreated.

You don't seem to understand (but you should if what you say is true about your inability to get the ASV that YOU have decided you want and YOU have decided that you need) that just because ASV might be the best thing doesn't mean it is easy to get. There are hurdles to jump to get ASV even if the need is standing there screaming out at you...and those hurdles take time. Might as well use the time (like you got any choice because you need to treat the OSA anyway) and use the cpap and see if you get lucky and are in the 1/3 that it works on.

So if a person doesn't have a money tree in their back yard where they can just go on the gray market and get an ASV...and last I knew there's no one pooping out ASV machines for free...what do you expect someone with OSA to do if they get an ASV machine?? Just wanting one because YOU think you need one isn't going to be enough to have the doctors get on board and/or get insurance on board.
The OSA still needs to be treated and there's a chance...1 in 3 that it might work out for a person that is all they need...that the centrals will go away.
Maybe not as fast as you want but if that's your only option...hey, it's better than no option.

I can see it now...I go into my doctor's office and declare I MUST have an ASV because I had 3 centrals last night and mr know it all on the forum says that's the best thing and I shouldn't accept anything less. That's going to go over really well. It ain't gonna happen.
Do you not have any common sense at all? People have to work within the system and do the best they can with what they have.

How's your way of doing things working out for you? Still don't have the machine do you? Are you even using a machine at all? What was your diagnosis? Not the one you came up with but the one on your sleep study.

Pugsy wrote:. . . the 1/3 . . .

I believe the source said "about one third to two thirds of patients."