When to worry about centrals?

After 2 weeks on my APAP, Sleephead has marked about 14 events per night as centrals, while only a couple of OA's and Hypops per night. My average AHI for the same 2 week period is 2.80.
On 2 of the days, I have observed Cheynes Stokes respiration.
I have the opportunity to purchase the ResMed ASV machine for $1k.
The process for Medicare and the slowness of the sleep doctor plus the delay in booking sleep studies are inviting me to take my therapy into my own hands. If I need an ASV (and that is the question I am asking), It would be at least March till I can jump through all the hoops with Docs, sleep labs and insurance.

Should I go ahead and buy this machine at this low price? Do I need a machine like this, or is the result of the APAP satisfactory. I have yet to feel any of my tiredness and fatigue lift.

Here is one of the nights with CSR.

Exactly which ResMed model ASV can you get for $1K?
If it is the ResMed AirCurve 10 ASV.....I would seriously look at it.

I don't know why your centrals seem to want to hit only late in the night. Plus you had them happen even without ever being on cpap..so they aren't caused by the pressure itself. They were present on your diagnostic study. It's not what is usually seen when people have issues with centrals but it is what it is.

I have always thought that ASV would be a more appropriate machine for your situation. It will treat both the obstructive stuff and the centrals when they pop up.
I think we already talking about the one potential contraindication...congestive heart failure (if you have it fairly bad) it might not be a good idea.
That's a maybe bad anyway. If your heart is fine I see no reason except the cost to not try it.

Now will it fix the fatigue issues? Don't know because your fatigue may or may not be related to sleep apnea itself. It happens to a lot of people...they have fatigue but the fatigue isn't related to sleep apnea and the machine (no matter which one they use) can fix a problem that isn't caused by sleep apnea.

If you were a family member of mine...and your heart was fine...I would find a way to get you an ASV to try.
Most likely give you the one I had to try out and see how it does. I have the ResMed S9 Adapt. I don't have problems with centrals but I used it just for the obstructive stuff. Tried it on a lark and found out I really liked it.

If you do elect to try ASV you will need some help in setting it up (it's a little bit more complicated) but one of the reasons I like the ResMed AirCurve 10 ASV or its older brother the S9 Adapt (same machine in different packaging now discontinued) is the settings are minimal. While not a plug and play thing....pretty close once we get EPAPs set.
I can help with setting it up.

If you do elect to try ASV on your own...don't expect an overnight miracle in terms of fatigue relief...it takes a while for the body to get used to the way ASV does things and that's assuming your fatigue is related to the central apneas you have.

Pugsy, it is an Airsense 10 ASV that is for sale. It supposedly has few hours - I think it belonged to someone who passed and their family is selling it. I am a little nervous about buying it since their would be no guarantee, but the price sure is right! (Someone might have already bought it while I'm typing this posting...ugh). I know I can't affort to gamble on buying a brand new one...I know what they cost on cpap.com.

I do not think my centrals are caused by the APAP...you are right in remembering I had them at my orig PSG (73 of them in the late night)..while having no OA's on that PSG.

I do not have CHF in any serious way. (Grade 1 LVDD-Which is common if not normal for my age (69), I had a complete heart workup. It was the cardiologist who sent me to the sleep study.
I have spent the last year trying to find out why I was so tired all the time...Thyroid, Vit B-12, Prostate Cancer..Heart..all negative.
I do think the sleep doctor would like me to have an MRI on the brain to see if there is tumors and I had a stroke. (I doubt that is the case, but who knows!)
I knew my sleep was lousy cause I would wake up many times a night, but since I did not snore, I didn't think about Apnea...but the CardioDoc did!

I have watched LankyLefts vids on the ASV and its settings...I would hope you would review them also. I may be able to get the Sleep doctor to give me a set of settings, but I don't know how she will react to me getting my own machine. I hope it is no problem.

I sort of feel an urgency here to get the right piece of equipment...do you think I am overreacting? or is this a serious matter? If I went through all the hoops, I think it would be March before I would finally get the ASV (assuming the doctor thinks the same as you do!). My next appointment in Jan 10. She would them schedule the next study (in 7 weeks from then--that how far they are backed up). Then I would need another appointment with her, and she would prescribe the machine. I just think that process needs short circuited!

I have never been known for my patience.
I wouldn't want to wait if I were in your shoes and if I had the money I would give the ASV a try...hey, that's how I ended up with an ASV of my own.
No way would I ever qualify for insurance to pay for one.

Here's the deal on the maybe fatigue being caused by sleep apnea in your situation. It's a maybe...so please don't take it as the gospel but it's a strong enough maybe that IMHO it's worth trying to fix it.
Any apnea event can cause arousals or fragmented sleep and it's the fragmented sleep that is a real big culprit in not feeling so good during the day.
So the arousals fragment the normal sleep architecture that is need for the restorative powers of sleep to work their magic. We may or may not remember the arousals but they mess with sleep architecture just the same...so we don't get the nice normal progression of the sleep stages in the nice normal % of needed time in each stage.

Now you remember a lot of awakenings...so it's safe to assume there are probably more that you don't remember. It's possible (remember it's a maybe) that it's the arousals/awakenings that is the cause of the fatigue. If we can fix the cause of the arousals...then maybe we can fix some of the fatigue issues. Lots of maybes but not impossible maybes.
You are having enough centrals that they can sure be causing arousals that could be messing with the sleep architecture.
If we can fix the centrals (ASV breathes for you) then maybe the arousals/awakenings will reduce.
Unfortunately there are a lot of things out there that can cause arousals/awakenings and sleep maintenance insomnia (that's where we have trouble staying asleep and if we remember a lot of awakenings we are having trouble staying asleep). Medication side effects are one potential cause...life in general (stress) is another possible cause...along with external factors we have no control over like in my case I have a dog that when she gets restless I hear her toenails on the hardwood floor.

Since we know that there is a known potential culprit that MIGHT be responsible for the fatigue then IMHO it's worth trying to fix it if at all possible.
The beauty of the ResMed AirCurve ASV...it can be configured in many ways even as a fixed cpap or made to function like your current machine if we wanted to so the worst case scenario if you bought the machine you would have a back up machine that costs a little more than what a person might get as a back up machine.

Now I have no idea how your doctor might react to this little experiment but it can be made (with setting tweaking) to function just like your current machine. He may or may not be willing to help you with the initial settings to let it be a true ASV and breathe for you when you have a central apnea...if he isn't...(whisper)...I know how to do it.

If for some reason you find that this current ASV has already sold...we can help you find another one. Usually most people don't have $1K laying around so those machines don't typically move all that fast. If that one has sold....we can probably find another one but might take just a little bit of time. I have seen them for around $700 (now those do sell quickly) but we can try to find one. I know a couple of people who could maybe help out that I trust enough with that amount of money to deliver.

Thanks for taking such a concern

I am waiting and hoping that my doctor contacts me today (before I try to buy the machine). I sent her a letter with some of my SH charts and some oximetry charts. (last week I got my Pulse Ox to record and am correlating that info with the SH info.) The Spo2 levels during a spat of centrals fell into desaturation 51 times for a total of 24 minutes under 88% O2 level! I thought she should know this. It seemed to me that such a low oxygen level may well be an explanation for my fatigue. Since then I have had somewhat less troublesome rates on several days, and some days I am normal. I have only been recording the O2 or 6 days now.

I wanted to ask her in writing if she could expedite this process for me, but she has not called back yet. I was expecting a call yesterday.


One tech question if I do this...if I put my current ResMed SD card in the new machine, will it work?; and will I appear to be in compliance for medicare purposes (so I can keep getting the supplies/masks/etc?)

That low of O2 most definitely needs to be address and could very well play into the fatigue.

Allessio77 wrote:One tech question if I do this...if I put my current ResMed SD card in the new machine, will it work?; and will I appear to be in compliance for medicare purposes (so I can keep getting the supplies/masks/etc?)

No, the old card won't work in the new machine for what you are wanting but compliance can be met with the new machine...doesn't have to be met with the old machine. You just have to be using a machine...any machine....to satisfy compliance for the mask, filters, etc side of the equipment.
For the AutoSet...compliance you would have to satisfy it but you may be close to that already...it's 70% of 30 night (consecutive) that you use the machine for at least 4 hours. That's all that is needed and then Medicare doesn't care about the machine. Aren't you getting real close to having had the AutoSet for a month??

I have used my machine for 14 days straight with 100% compliance, so I have 7 nights to go.

Would I take my current machine back to the DME? or keep it and let the DME know I bought an ASV?
Where would I get a new SD card. I assume the one coming in the used machine I am buying would either have no SD card or someone else's SD card.

Here's what I would do if it were me in your shoes.

First of all the machine should come with it's own SD card...but if it doesn't you can buy one at Walmart that will work or you can steal the SD card out of the AutoSet and use it. If you get a ResMed ASV it won't like the old data from the AutoSet on that card and will want you to erase the old data so it can use the card. It is just the way ResMed machines work..they don't like any other data on the card.

As far as the AutoSet and Medicare...once you have used the ASV and determine it is what you want to use forever you can either keep the AutoSet as a backup but it isn't helping so I wouldn't do that.
Medicare does the 13 month rent to own (assuming you have regular Medicare and not one of the Advantage plans...let me know if you have one of the Advantage plans) where they pay a portion of the rent to own costs over 13 months and your responsibility is the 20 % of the allowed amount which is typically picked up by any supplement you might have). So you are going to have 13 months of expenses for the AutoSet...I would return it and no incur those expenses if it was me because the AutoSet really doesn't help you all that much and would be an inferior back up machine.

Should you wish to do that then you just give the new machine information to the DME and they run with it. There's no need for the DME to have to physically sell you the machine for it to be used for compliance or data accumulation. I have Medicare...Medicare as never bought a machine for me but I have a DME that I get my cpap supplies from as I need them per Medicare replacement schedule.
Normally once the 21 day compliance thing has been met the DME doesn't do anything in terms of following your usage unless the doctor acts them to do so. It's just there. I haven't seen a sleep doctor in over 8 years and I still get my cpap supplies from my DME without a hassle.
Now some DMEs have elected to have their own in house policy about requiring a new RX annually...which means a visit to the doctor but that's easy to get if they want to do that. Mine doesn't.

For me...I wouldn't want to be paying for the AutoSet for 13 months and have it really not be a very good backup machine. Now if it was semi good..yeah maybe but in your situation it really isn't all that great.

But before returning it...I would want to make sure the ASV was what I wanted to be using. I can't imagine it not working well for you but you never know about this stuff until you use it.

If you have a Medicare Advantage plan...let me know as things can get a bit more complicated with those plans depending on the plan and if your plan is like mine .....for sure return it. Will explain in more detail if you have a Medicare Advantage plan.

I personally would not want to be on ASV if I had an AHI < 5 on CPAP.

As Pugsy mentioned, there are safety concerns about ASV based on a study which showed risk in people with certain heart condition (congestive heart failure with low ejection fraction). What I would add to that is that since know one knows why that group had problems, experts don't know what that safety signal means for ASV safety in other groups besides the one with that heart condition.

If I had an AHI > 5 which was more than 50% centrals and normal heart function, then I would consider ASV. Otherwise, pending further studies to establish a more solid safety record, I would not.

FrederickRose wrote:I personally would not want to be on ASV if I had an AHI < 5 on CPAP.

As Pugsy mentioned, there are safety concerns about ASV based on a study which showed risk in people with certain heart condition (congestive heart failure with low ejection fraction). What I would add to that is that since know one knows why that group had problems, experts don't know what that safety signal means for ASV safety in other groups besides the one with that heart condition.

If I had an AHI > 5 which was more than 50% centrals and normal heart function, then I would consider ASV. Otherwise, pending further studies to establish a more solid safety record, I would not.

Thanks for your comments.

I do not have a heart condition with a low injection fraction...my fraction is between 55-65% as estimated on an echocardiogram 3 months ago. I do have more than 50% centrals both now on APAP and on the original PSG (where I had 73 CA's and no OA's but a couple of obstructive hypopnias).

My sleep doctor works at the same practice as my cardiologist. (I presume they are consulting)

After my sleep studies, the sleep doc reviewed my cardio testing and indicated that she was going to prescribe an ASV until she noticed that my PSG was done at a higher altitude than my residence, so she opted for the APAP to see what would happen and track my centrals at my residence altitude.

Given that info, would you feel a little safer Frederick?

I have all sorts of heart problems, but I don't have to worry about centrals, My machine doesn't really show them, so out of sight out of mind, I can obsess over other things going on. Jim

I may never get a new generation, just for my piece of mind. I check my AHI and Leaks, that's all I need, if they are under control and they are I'm Happy.

Still waking up after 12 years.

The studies that got everyone in panic mode about using ASV weren't ideal studies IMHO.
Small group of people used...those people were already really sick with CHF and ejection rates below 45 and they didn't use the machine even 4 hour average.
So they took some people who were really sick and didn't come close to using the machine all night and the end result was an increase in chance of mortality.. Was it because they were really sick in the first place with a bad heart...or was it because they didn't use the machine for anywhere near recommended hours of us or was it because ASV triggered something to make a bad situation worse???
Would this group of really sick people maybe had a better mortality rate if they had used the machine all night??? We don't know.

I was using ASV for OSA when this study was released.
1....I have no history of CHF of any sort
2....I use the machine all night and not half the night every night...so hours of use 6 to 8 and not less than 4 on average
So I wasn't afraid to continue using it.

Now when they do a study on more than a tiny group of people without 1 foot in death's door from CHF and the people use the machine all night instead of half the night and the results look scary. Then I will rethink my position on ASV use in people not already really sick.
Now if a person is really sick already and has CHF and ejection rate of less than 45....by all means have an in depth discussion about potential risks and consider alternate ways of treating the centrals. Like the ST models or something like that.

Great information Pugsy.

I think I would take back my current machine... Let the DME know about the new machine (after I test it out, of course)...Get my supplies from the same DME according to standard schedule.
I have an empty SD card here at home of the same size. Will the new card in the ASV machine need to be re-registered with ResMed?...my current machine sends info daily to ResMed (which the DME or DOc can access)

I do have original Medicare plus a Plan F.


Ok, now I have to make up my mind and talk to the seller...I hope the doctor calls me today...and I will let you know if I get the machine I have my eyes on (or if I need your help in finding a similar machine). I really don't think staying with my current machine is the way to go...it doesn't sound like you do either!

Pugsy wrote:The studies that got everyone in panic mode about using ASV weren't ideal studies IMHO.
Small group of people used...those people were already really sick with CHF and ejection rates below 45 and they didn't use the machine even 4 hour average.
So they took some people who were really sick and didn't come close to using the machine all night and the end result was an increase in chance of mortality.. Was it because they were really sick in the first place with a bad heart...or was it because they didn't use the machine for anywhere near recommended hours of us or was it because ASV triggered something to make a bad situation worse???
Would this group of really sick people maybe had a better mortality rate if they had used the machine all night??? We don't know.

They did have a reasonable control group. Here is a summary of that study from a recent review at UpToDate.com:

Increased caution when considering the use of ASV in patients with heart failure is based on results of SERVE-HF, a multicenter, open-label trial that randomly assigned 1325 patients with moderate to severe predominant CSA (AHI ≥15, central apnea index >10) and symptomatic heart failure (defined as an EF ≤45 percent and New York Heart Association [NYHA] Class III, NYHA class IV, or NYHA class II with ≥1 hospitalization for heart failure in the previous 24 months) to ASV plus standard medical therapy or medical therapy alone [16]. The primary endpoint was death from any cause, lifesaving cardiovascular intervention (cardiac transplantation, implantation of a ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization for worsening heart failure. Secondary endpoints included time to death from any cause, time to death from cardiovascular causes, change in NYHA class, and change in timed-walk distance. Results included the following:

●The mean age of the patients was 69 years, and approximately 90 percent were male. The majority of patients had NYHA class III heart failure, and the mean ejection fraction was 32 percent. Approximately 50 percent of the patients in both groups had an implanted defibrillator device. The mean baseline AHI in the two treatment groups was 31 to 32 events per hour, and central AHI to total AHI ratio was 81 to 82 percent.

●ASV effectively reduced the number of apneas and hypopneas as measured by polysomnography: the mean AHI in the ASV group decreased from 31 events per hour at baseline to 6.6 events per hour at 12 months.

●The incidence of the primary endpoint was similar in the ASV group compared with controls (54 versus 51 percent; hazard ratio [HR] 1.13, 95% CI 0.97-1.31). In addition, ASV did not improve symptoms or ejection fraction.

●Compared with controls, patients assigned to ASV had significantly higher all-cause mortality (35 versus 29 percent; HR 1.28, 95% CI 1.06-1.55) and cardiovascular mortality (30 versus 24 percent; HR 1.34, 95% CI 1.09-1.65).

The mechanism whereby ASV led to an increase in mortality in this trial is not known. One possibility is that ASV led to a decrease in cardiac output and stroke volume in susceptible patients, such as those with low preload. Another possibility is that Cheyne-Stokes respiration serves a compensatory function in heart failure, and that ASV proved detrimental by diminishing this compensatory respiratory pattern [17,18].

The same author encourages caution for ASV use even in those without heart failure and low EF:

ASV remains an option in patients with hyperventilation-related CSA and a preserved ejection fraction, although treatment decisions in such patients should be individualized, and there is a paucity of direct data in these patients [15].

Patients who are already using ASV for other indications (eg, heart failure with preserved ejection fraction, primary CSA, treatment-emergent CSA) should be informed about the safety signal from the SERVE-HF trial; in some cases the balance of risks and benefits may still favor ASV therapy, particularly in patients who are responding to therapy and have failed prior CPAP.

From a different author but relevant:

Although there is not a universally accepted definition of continuous positive airway pressure (CPAP) "failure" in a setting of treatment of central sleep apnea (CSA), we define it as the residual apnea-hypopnea index (AHI) of 5 or above, with >50 percent of residual events of central origin.

So if I were the OP, I would not consider this a CPAP failure and would have concerns about a change to ASV.

FrederickRose wrote: So if I were the OP, I would not consider this a CPAP failure and would have concerns about a change to ASV.

So you are okay with being on APAP and having desats to the 50% range?
He sometimes has 2 hours of centrals...it's not like only 5 minutes of centrals.