Why so many Central Apneas?

Here is my data summary for the past four days:

(Day1/Day2/Day3/Day4):
5.7hrs/9.0hrs/7.3hrs/7.7hrs
Pressure= 8.8/8.8/8.6/8.2
Leak= 3.6/7.2/3.6/3.6
AHI= 2.2/10.5/4.1/1.2
Total AI= 2.0/10.3/3.8/1.1
Central AI= 1.7/9.3/3.8/1.0

I know that four days is not much data, but the one tendency that appears pretty sound is my Central Apneas represent roughly 90% of my Apnea. So, it looks like my Obstructive Apnea is being well addressed by the machine (my original sleep study showed about 50/50 obstructive vs central). However, is there something I should try to decrease the Central's?

Also, what is considered a decent leak rate?

TIA!

Hi, if this is what you have after 4 days, you're doing great! It does look as if on the second night there might have been a slight problem, e.g. the mask came out of place or something, as your numbers are higher, but then levels off the next two nights. I know it looks like your centrals are high proportionally then (and even on the other nights), but don't read it that way because unless you (in future) consistently get an actual high number of them - regardless of your other numbers - I wouldn't worry at all. Yes, they may be "half" of your apneas, but I doubt that half of such small numbers is meaningful at all and would only matter if on their own they were high (a lot higher than they are now). Definitely give it more time before jumping to any conclusions based on things as they are yet. And every machine and mask have different leak rates in relation to each other and you but yours are very low from this sample. It's not uncommon to have them in the 20's and even 30's on occasion. And not at all uncommon to have more centrals on sleep studies than you get once on Cpap.

Thanks for the response Julie. I am definitely happy with my progress.

I worded my statement ambiguously. My sleep study (pre CPAP) showed 1 obstruction and 1 central (one of each). I had 41 Hypopnea Events!

Now that I have my CPAP going, it seems that the hypopneas have essentially disappeared and the centrals are the source of 80% to 90% of my events every day. It seems that the CPAP has actually increased my Central Apneas. I'm not complaining, because the Hypopnea events are reduced enough to compensate.

So, I'm wondering why wearing a CPAP would increase my Centrals and if there is anything I can/should do to try to decrease the frequency.

It's not uncommon to have lots of centrals in the beginning, because your body /brain are not used to the cpap and the additional air pressure. Most likely at your pressure of 8, centrals will not be an issue. Even with such a high "index", I'd bet you money those CAs are clustered around the time you fell asleep, when you woke up in the morning, and if you woke up at night at any point. You can call them sleep onset central apneas.

However, did they do a titration study (with cpap) as well , and if so did they see central apneas there? That's the only way they will know whether you have a problem with central apneas.

Give it some more time. Get used to the pressure and the mask and sleeping with it all night. Eliminate mask leaks. Get a good hose management system. Make sure your pillow is comfortable. Get the software to see when and how the CAs are happening (eg mask leaks, what time, etc). That is the best you can do right now. If you do have a real issue with centrals, then you will need to go back to your sleep doctor. A normal apap cannot handle severe central apnea.

I also had some centrals during the sleep study as well as the titration. In the beginning on Cpap, first few weeks or so, I had a few CAs most nights. It was because I wasn't used to the pressure yet. Now I only get them at above 11cm, but my pressure is 10.5cm. BTW I also had basically only hypops during my first sleep study.