@gramps- I am not real familiar with central sleep apneas, but I've been told by my sleep specialist that he wants to keep mine below 4. He has me on a pressure of 11 and that seems to keep me well below 4's, but recently had a 4.9 which was totally uncharacteristic for me? I seem to have issues more often with the mask leak sad face and the last time I was in to see my specialist he said he is not real concerned about that, but rather the AHI's. Since mine is often 1.5- 2.5 he said no problems here.
I could understand if your Dr. would want to 1st try increasing the pressure as a 1st step to see if your apnea's decrease.
Makes sense to me. Hopefully that will bring you back to those restful sleeps you were having before. Happy Zzzz's.....
Jim @thankful