(11-30-2016, 11:02 AM)caseyfontneau Wrote: Also More for curiosity, but what is the logic behind turning off EPR and thinking it will help with the centrals? I guess I don't understand centrals well enough to know what's causing them to begin with.
Throwing in my two cents.
While a few people do seem to have CAs that are triggered by using EPR, many people do not find the EPR setting relevant to the number of CAs they experience and some people find that they have fewer CAs with EPR = 3. And in fact, some insurance companies will first require a patient diagnosed with complex sleep apnea to try out a plain bilevel machine before authorizing moving to an ASV machine. The reason behind their rule? Some complex sleep apnea patients have no problems with machine induced CAs while on bilevel with an appropriately chosen PS even though they do have problems with machine induced CAs on CPAP/APAP.
Here's the thing: The CA clusters are triggered by a CO2 overshoot/undershoot cycle, and it doesn't much matter if the start of the cycle is an overshoot or an undershoot. Too much EPR may trigger "blowing off too much CO2" which can trigger the overshoot/undershoot cycle to develop. But not enough EPR may trigger "blowing off too
little CO2" which can trigger a CO2 undershoot/overshoot cycle with the exact same problem of lots of CAs at the nadir of the cycle.
My advice is this:
1) If turning off EPR makes you more uncomfortable (and less likely to use the machine all night long), then you're better off keeping EPR on. You might try decreasing EPR if it's currently set to 3. But you might also try
increasing EPR to 3 if it's set to 1 or 2.
2) If turning off EPR does not lead to more discomfort and it reduces the CAs, that's great---you've identified part or all of the problem.
3) If turning off EPR leads to MORE CAs, then turn EPR back on and consider increasing EPR to its max setting. If using EPR = 3 leads to fewer CAs than using EPR = Off or EPR = 1, then that's great, you've identified part or all of the problem. And in fact if the number of CAs is still to high, but is less at EPR = 3 than it is when EPR = 1 or EPR = OFF, then that may indicate that a simple bilevel with a PS = 4 or 5 might do the trick for you without the need of going all the way to an ASV machine.