New mask: increased AHI but lower leaks?

Hi all -

I have been CPAPing for about 18 months and have been sleeping well using the P10 mask plus mouth tape to keep my mouth closed. I don't love the mouth tape but it works. My normal results are around .5 AHI and leak rate averaging around 8 or 9 L/min. I am 100% a side sleeper.

Recently I have been having some shoulder issues and have been trying to learn to sleep on my back. After 50 years of side sleeping it's not easy, but I am trying to get used to it. Unfortunately, the mouth tape seems to fail when I'm on my back, because as the pressure increases during an event, air starts slipping out the sides of my mouth or my cheeks puff up - eventually loosening the mouth tape. No good.

So, I tried a bunch of full face masks and I've found that the F40 seems to work pretty well. It took a few days of fidgeting but it's comfortable (enough) and not leaking a lot. i still mostly sleep on my side, but whenever I remember to try i'll rollover on my back of often sleep a tiny bit that way. I also noticed that even when I'm awake, if I'm on my back my throat starts to close up (just gravity causing obstruction, it feels like) so I bumped the min pressure from 6 to 7 and that seemed to help.

I had noticed for the first week or two I didn't quite feel as refreshed after sleeping, so i loaded up OSCAR for the first time in a long time. From what I can tell, it's leaking LESS than the other mask, but I'm having MORE events, and my AHI is now tripled to 1.5 or 2 on some days.

I am wondering:

- could it be that if I'm on my back, I just need more pressure to keep the airway open? maybe the min pressure needs to rise a little more?
- I know that AHI of 1.5 is still fairly low, maybe just ignore all of this?

I know that some people here are masters of interpreting the OSCAR data, so I'm posting below. Any input much appreciated!

Shnoozer wrote: ↑

Thu Apr 30, 2026 1:32 pm

I am wondering:

- could it be that if I'm on my back, I just need more pressure to keep the airway open? maybe the min pressure needs to rise a little more?
- I know that AHI of 1.5 is still fairly low, maybe just ignore all of this?

yes and yes. if you are sleeping well and with your ahi at 1.5, I don't think you need to change anything.

back sleeping is my kryptonite. my tongue slides back in my throat and my ahi can easily triple. I too have sore shoulders and am seeing a physical therapist, which is quite magical. and medicare pays for it.