Funky flow curve with taped mouth

[canadave]

Howdy!

I'm new to the forum, and only been on CPAP for three months. I'm using a Resmed N30i cradle and tape my mouth with 2in cover-roll stretch tape, as per LankyLefty.

Subjectively my sleep feels pretty good now, but looking at my OSCAR data it seems like there is still room for improvement. Sometimes my arousals are preceded by a noticeable change in the flow rate curve. Do you have any idea of what could be causing this? Based on the wiki (Optimizing_therapy) it looks to me like the curve associated with mouth expiration... but I can't see how that could happen while my mouth is taped. When I go to bed and when I wake up I try puffing my cheeks to see whether the mouth is properly sealed, and have not had a problem with it -- I shave every night before going to bed, so the tape sticks very well.

Here's the funky-looking flow rate curve (taped mouth). First, going from normal breathing to funky breathing.
   

This is the same event, showing how the funky breathing turns into a hypopnea and arousal a minute later.
   

Overview of the night (I had a cold):
   

Many thanks!

[clownbell]

EPR is currently off. May I suggest EPR of 3, full time, to help treat hypopnea and flow limits.

[multicast]

This https://sites.google.com/view/palatal-prolapse may be helpful.

[canadave]

Thank you, Multicast. Haven't read everything yet, but it makes sense.

It sounds like it would be a good idea to talk to an ENT and perhaps invest in an oximeter to find out how serious it is in my case.

[canadave]

EPR is currently off. May I suggest EPR of 3, full time, to help treat hypopnea and flow limits.

I can give that a try. Can you elaborate on how that would help?

If the underlying issue is palatal prolapse, a lower EPAP would increase the flow rate during expiration. Wouldn't a faster flow increase the probability of prolapse?