Totally Confused by Airsense 10 Data - Centrals - Problem machine... ?

[mymontreal]

Diagnosed with fairly severe OSA in 2009

Had several overnight sleep studies and all showed AHI levels between 30 & 60 events per hour, with almost all OA and H, with a very occasional Central Apnea event showing up.

Prescribed APAP, but just could not get used to it - too many problems with aerophagia, even when pressures fairly low...

Subsequently had UPP surgery and a then a dental appliance - helped a little bit, but apnea still pretty bad and now sleep center doctor convinced that I really need to have MMA surgery...

Decided to give APAP another go before making any decision on MMA surgery - purchased a new Airsense 10 APAP machine and whilst I'm using it and tolerating it pretty well, the data results are totally confusing me & no idea where to go from here... ??

Pressure range is set at 5-12 (as per Dr advice). My average AHI is showing as between 5 & 10 and the APAP pressure never seems to increase beyond about 7.5.

The machine display, Sleepyhead & ResScan all seem to confirm that the resulting AHI of between 5 & 10 is not due to OA or H events, but almost entirely due to Central events...

I AM VERY CONFUSED BECAUSE HISTORICAL SLEEP STUDIES HAVE ALL SHOWN MY SLEEP APNEA TO BE OBSTRUCTIVE (with no real centrals)...

How is this possible and where do I go from here ?

- I understand that high machine pressures can often induce Central events, but my pressure is maxing out at about 7.5, so I doubt that is cause ?

- Presumably my APAP is not going higher that 7.5, because it's sufficient to deal with most OA & H events ?

-Is it possible my new Airsense 10 APAP is not working properly... how would I even know ?

- I am a little skeptical of the data, particularly because the max pressure is so low (it's maxing about 7.5, but most of the time it seems to be at 5.0 or 5.5...!) - on my previous APAP machine 6 years ago, I needed a pressure of 12-14 to resolve my high number of OA events...

- Is this "Central" apnea data real, or is it just an anomaly of the machine... obviously if my main problem was central apneas, it would be pointless to go ahead with MMA surgery...

Would welcome some input from anybody who has seen anything similar - I know you will want to see some data graphs, but not sure what to post... ?

Many Thanks

[Sleeprider]

If you're using EPR at 3, try dialing that down to 1 or off. CA events can be caused by the pressure support of EPR. Posting your #Sleepyhead data would allow a better analysis of what is going on.

[trish6hundred]

Hi mymontreal,
WELCOME! to the forum.!
It's good that you decided to try again with CPAP therapy before you go through more surgery.
Hang in there for more responses to your post and good luck to you on your CPAP journey and also with your decision on surgery.

[mymontreal]

Thanks Sleeprider - I will try that!

EPR was turned on by my provider & it's probably not needed, particularly if my actual pressures are ranging between 5 and 7... ?

The resolution may not be high enough, but I will try posting a small PDF of Sleepyhead data here (< 200k so within the newbie limit...) now. If it's unreadable, I will post another one tonight.

[Sleeprider]

That is a lot of CA and some periods of periodic breathing flagged. I would turn off EPR and see where it goes. Did you ever receive a titration study?

[Rcgop]

That is my very problem too. Low pressure, all centrals. I started with EPR off and now at 1. I just got the results of my heart tests. EKG, ECG, Holter monitor, and nuclear stress test. All results normal. I am currently testing a theory I have. I have been using a medium (P10 pillow). Started using a large a couple days ago and "I think" it has helped on the centrals (clear airways). Still not good enough though. I get a lot more air through the large and maybe that is too much. More comfortable but I wonder if I am over breathing and causing the cycle to get started that way. I am sure it is sleep/wake junk as I am always half asleep whe it happens. I just can't get it to stop. OBTW it does not happen when I am asleep.

I think this is my last hurdle to get over to have my system dialed in. Here's my plan of attack for this.
1. Stay on the large pillow for several more days and see if things get better.
2. Start lowering both min and max (1 at a time) but not below my 90 % pressure. Which is 8.25. Yes, I did a month long study.
3. Turn off EPR.

I hope my experience sparks some new suggestions as I will be following this thread for new ideas.

[richb]

Hi mymontreal. Welcome to the Apnea Board. Yes our machines can cause Centrals (CAs) because the pressure differentials caused by using EPR washes out CO2 and tricks your body into thinking you have done enough breathing. Sleeprider and Rcgop make good suggestions especially about reducing or turning off EPR. It does seem that your machine is treating your OA and H events at a fairly low pressure. That is very good news because there are more leak issues at higher pressures. It is also easier to eliminate EPR when pressures are lower. Keep us posted.

Rich

[robysue]

mymontreal,

First a very important question: How long have you been using the CPAP this time around? A few days? A few weeks? or a few months?

I want to piggyback on what richb said. A small percentage (maybe 10-15%) of PAPers have problems with "pressure induced central apneas" that are caused by CO2 washout. For most of these people, the problem usually goes away on it's own as your body adjusts to sleeping with the machine, and so most sleep docs (and all insurance companies) tend to take a wait and see attitude if a lot of machine scored CAs show up once a person starts CPAP/APAP. Most of the time, the pressure induced CAs start to resolve after a few weeks of PAPing. But if you are still seeing this kind of data on most nights and you've been at it for 2 months or more, it's time to insist that the sleep doc look at the data and figure out if you are in the very small group of OSA patients who wind up developing complex sleep apnea. Complex sleep apnea usually requires changing the APAP out for an ASV machine, although your insurance company may insist on first swapping the machine out for a bilevel PAP.

As richb indicated, some people do find turning EPR down or off fixes the problem. Some people find that the EPR setting is completely unrelated to the number of CAs, and a few people even find that they do better with EPR set to the max. So play around with EPR and see if turning it down or off makes the data get better or worse. Also pay attention to whether you feel just as comfortable with a lower EPR as you do with EPR = 3.

Finally there's another thing can also be important when evaluating machine scored CAs, and that's how often are you awake and tossing and turning while using the machine? And do the wakeful, restless periods correspond to when the CAs are being scored. That's because some people have a tendency to have a CA or two when they are transitioning from WAKE to SLEEP. These are perfectly normal and on a diagnostic sleep lab they're not even scored---unless they are so numerous that the CAs clearly indicate that the CAs prevent the patient from being able to transition all the way from WAKE to Stage 1 Sleep to Stage 2 Sleep. Stage 1 sleep is not stable sleep, but Stage 2 is stable sleep. Well it turns out that if we're doing a lot of "dozing" while using the machine, there can be a lot of CAs that get scored. Some of them are likely sleep transition CAs. Some may represent some trouble going all the way to Stage 2 sleep. And sometimes they're just misscored normal wake breathing. Our machines don't know whether we're awake or asleep and wake breathing is a lot less regular than sleep breathing; that means that our machines can be fooled by wake breathing.

So it's also important to ask: How much time do you think you are sleeping with the machine as opposed to dozing or tossing and turning with the machine?

[mymontreal]

Thank you to everybody for providing such great feedback and suggestions - I had no idea that the topic of Central Apneas would be so complex...

As a starting point, I turned off EPR on Weds night/Thurs am to see what impact it would have - it was a pretty bad night... It's only one night's data (so may be meaningless), but I did not expect it to have such a big impact... It did reduce the CAs somewhat (from 10/hr down to about 5/hr), but I saw a huge increase in my 95%/Max pressures, which made it very uncomfortable, lot of aerophagia problems and quite a few leaks - had to turn it off after about 4 hours...

I will attempt to link to my first SH screenshot on Photobucket:

** Tried to include link to my screenshot on Photobucket, but I keep getting following forum error message... ?

You cannot post clickable links to this forum threads and posts. Minimum post count is 4 posts. But your post count is just 2 posts.
You are not allowed to post links in this forum.
You are not allowed to post images in this forum.

Surprised that the pressure went so high (95% pressure was 11.4) , as it seems to have been averaging just 5-7 over last couple of weeks... Needed a break from the hose last night, but will probably try again with EPR=0 this evening

Apologies, I probably have not included the most appropriate SH graphs, but if someone can clarify, I am happy to post a new screenshot.

In answer to a couple of specific questions:

Sleeprider - Yes I did have a titration study 5 or 6 years ago when I tried CPAP initially - I can lookup the report, but I seem to remember initial CPAP pressure was set to about 10 and it caused Total AHI to be about 2.0 - don't remember any mention of Centrals, Periodic Breathing, Cheyne-Stokes breathing etc. - let me know if I should dig it out ?

Robysue - I've only been back on CPAP for a couple of weeks, so it is early days - not really sure about the "tossing & turning" time... I certainly don't have much time where I seem to be wide awake... ?

Many Thanks!

[Sleeprider]

After your next post you won't get error messages when you try to link images. It takes 4 posts to reach that threshold. Just reply and try again.

The fact you reduced events with less EPR is kind of significant. Even if you limit the maximum pressure to 10, try it again and let's see where that takes you. Limiting maximum pressure may help you make the transition, and we really need to see if the CA goes away without the pressure support (different IPAP/EPAP pressure).

The main point of the sleep study and titration is that you have the records. If the study had shown central apnea, then this would have been supportive of the theory you may have CPAP induced complex or central apnea. That suggests that the centrals are a more recent phenomenon and we may find another way to deal with it.