Ok, I'll attempt to answer your questions, except my age.... although I'm close enough to your age and feel every bit of those years.
The change from Medium to Very High Trigger did bring your CA count down, but if it doesn't "feel" right to you, then change it to High.
Trigger Sensitivity: Adjustable trigger sensitivity can be used to optimize synchrony between the device and the patient’s own respiratory efforts.
As far as using EPAP 8 vs. 9, there isn't much difference in your stats. I thing the Nov 4th chart looked pretty good. But if EPAP 9 felt like too much pressure, then try 8.4 or 8.6 (somewhere in between).
Here's the formula: EPAP + PS = Inspiration. (9 + 4 = 13) When you add PS to EPAP (exhale pressure), this gives you the starting inspiration. So in your case: Inspiration 13+ with exhalation at 9+.
That opening message in
OSCAR doesn't mean you were at a certain pressure for 95% of the night. It means you were at that pressure or lower. (Note the "or lower"). When you look at your chart, toward the morning where the clumps of apnea show, the air flow attempts to raise the pressure to clear the Obstructives, but it usually fails with positional apnea. So at that particular time, you will see the higher pressure.
I can better understand why you might be experiencing some positional apnea with the tongue surgery and bite plate you are using. That's a lot to deal with. At this stage, I would just keep your settings where you feel most comfortable, as your chart for Nov 4th is decent.
