Perfect AHI - poor sleep - opinions please!

It's been a (very long) while since I have posted....

I was diagnosed with OSA in 2011, and after not having got on with an APAP, I purchased an S9 VPAP machine. Ahhhhhh, bliss, good sleep for the most part.

In a post I made in 2012, I outlined how my then-new VPAP was working:

viewtopic.php?f=1&t=76939&p=701790#p701790

The issue I outlined then appears to be back. For the last few weeks I have noticed that even though my numbers are usually very good - mostly AHI is 0.0 - I wake up at least once during the night and I just don't feel as rested.

I got round to having a look at my data yesterday. In most cases, even with an AHI of 0.0, I see breathing/flow disturbances after around 3.5 - 4 hours in bed, followed by 6-8 second apnoeas which of course don't register on the AHI score. These wake me up, and after going back to sleep the same thing happens a couple of hours later.

I have always used my VPAP machine in non-auto 'S' mode with IPAP/EPAP of 14.0 / 9.6 cm H20 respectively. So as a test, last night I raised the IPAP/EPAP to 15.2 / 10.8 cm H20.

This resulted in an AHI of 3.6, and some grogginess this morning. Breathing out felt rather more difficult, and indeed I recall in my brief use of an APAP machine in 2011, I didn't like the feeling of a CPAP pressure around 11 cm H20. I haven't looked at my data yet.

So tonight, I am tempted to either:

(i) Set EPAP at its previous level of 9.6 cm H20, but keep IPAP at 15.2 cm H20, keeping the machine in 'S' mode, or
(ii) Put the machine into Auto mode, starting with a minimum EPAP of 9.6 cm H20 and PS of 4.4 - recreating my previous 'S' settings - and setting maximum IPAP to something like 16 or 17 cm H20.

My previous 'S' settings work well for the most part, and so I am tempted to try option (ii), although I don't know how quickly, or even if, my machine will be able to detect the breathing disturbances and therefore raise the pressure, and for how long.

Looking for your views on what route I should try I was titrated at 10 cm H20 incidentally.

As a general rule, an AHI of 0.0 indicates that sleep disturbances from OSA are not occuring and that changing pressures in not necessary. If a pressure change increases AHI, that is generally not a change to make.

Although breathing events can disturb sleep, it is also possible for disturbances to sleep to cause changes (pauses) in breathing. So the solution for your improving sleep may not always be a matter of improving settings on your PAP machine but may be related to finding out if something else is disturbing your sleep.

That said, posting pictures of your data may allow you to get comments from people who are experienced at reading the charts that show leak, flow, etc. and who can comment on whether your PAP treatment appears to them to be optimized.

perhaps if you put some charts up. someone may see something worth looking at.
It is normal to arouse/wake up several times a night, we normally don't remember it. it could also be totally unrelated to sleep apnea.