Maybe I just don't get it, but....

I was diagnosed last year with OSA. (22 hypopneas, no apneas or central apneas) I BARELY slept for the testing or titration. (2 hours each) My pressure was prescribed at 7. I tried for the past year to wear my mask, but woke up feeling suffocated every 2 hours or so. Changed masks a few times, but just couldnt get through the night. Dr thought perhaps nighttime panic attacks. The only way to sleep through the night was with AMBIEN, but I was on it nightly for 3 months and did not want to need meds to sleep forever. I felt that my pressure was not high enough. I spoke to my drs office and her awesome assistant there and I decided to try autopap. We ordered Resmed s9 and I have been on it 2 weeks. I am sleeping SO much better, at least 6-7 hours a night. My pressures were set 4-10. My ahi is 0.0 to 0.3 . I have shown an occasional central now and the average pressure is 9.8-10 My question is how I can show no events, but my machines pressure is at 10. Why is it raising to 10 if there isnt an event? Should my parameters be raised? Why am I now showing occasional CA?

An occasional central is normal for some people when transitioning between sleep stages. Events aren't the only things that raise pressure; snores or breathing in a way that indicates a closing airway will cause some autos to raise pressure to prevent events. Four is a low pressure to start out with. Sounds to me like you "get it" better than most.

You're showing no events because your machine is doing a good job of proactively preventing them instead of retroactively responding to them.

The machine can sense when things are leading up to an event (obstructive apnea primarily, and to a lesser extent a hypopnea) by the flow limitation and snore index. These are precursors to an "event" and will cause the machine to raise the pressure in response. If it all works correctly, no obstructive apnea. The centrals, or clear airway "events" do increase a little with this approach, but your numbers are SO good the and CA's are so few that it's nothing to worry about at all.

I'm in the "if it ain't broke don't fix it" school of thought, but you might talk to your doctor about raising your parameters a little if for no reason other than you might feel a bit suffocated when you start off the evening at only 4 cms. And if you are having a "bad night" you might need your machine to go a bit higher than 10 cm if your average pressure is already at 10.

The machine is not just responding to events--it is responding to flow limitation and snore, which are not reflected as events in the AHI. So, it is detecting that your throat is closing even though it doesn't become a hypopnea or apnea. The S9 is the first ResMed machine that detects Centrals separately from Obstructive apneas. I think the Respironics SystemOne Auto also detects the difference, but both of these machines just came out within the last year, so you may have been having some centrals all along, but they were just not distinguished from obstructive apneas.

thank you all so much for your replys. On my next visit I will ask about raising my parameters to 6-12 perhaps, but I feel relieved for all of you to say things seems ok so far. If I had been given my s9 to begin with, I would have been spared a lot of very anxious nights.

For the record, I think an awful lot of us have pressures set at 8-12; it seems to be the norm. 4 is ridiculous, and 6 not a lot better, but I agree that 10 is low for the ceiling as you're already going over anyhow.