I wanted to come back with an update and get some help. I've been experimenting with higher pressure support to see if that could resolve the flat-top breathing curve flow limitations I've been seeing, and it seems to work. It also allows me to drop my EPAP to 6, which seems to be plenty to resolve my obstructive events. For the last two nights, I've had my machine set to 6 EPAP and 14 IPAP. It does feel a little strong on the inhale, but it seems that the pressure support of 8 is sufficient to stop most of the flat-top breathing curves that I've seen for many months now, so I'm very encouraged by the success of the higher pressure support. I can handle it a little bit better because the minimum pressure is lower.
But I am still having an issue later into my sleep. Especially in the mornings, when I assume I'm in REM, my nose is just unbelievably congested. It's a dry congestion, and when I take the mask off to test out my breathing, I can barely breathe through my nose at all. And yet when I put the mask on, I'm able to push through most of it and breathe OK. I'm using a P30i mask and putting an elastic headband over my mouth to prevent mouth breathing, which seems to work pretty well and means I don't necessarily need to use mouth tape.
Seems that I'm having two primary issues:
Number one is that in the earlier parts of the night, my general flow rate seems to look fine to me (most of the time), but there are intermittent periods of spikes in my breathing pattern that I can't explain. I figured these would be precipitated by some kind of flat-topped breath, but I'm not seeing that anymore now with the higher pressure support, and yet these micro-arousals persist and are fairly regular throughout the night.
The second issue is that more toward the morning, it seems that my nose is blocking up really badly and that I am getting more classic-looking flow limitations. So I'm trying to figure out how to solve for both of these things. I do have an X30i mask, which I could try tonight to see if maybe that helps with the flow limitations I'm getting closer to the morning that are likely caused by the nasal congestion. But as many of you know, breathing through the mouth is not the best and potentially could cause more problems and also dries me out, which also could wake me up, so I'm not really sure what the best solution to that is.
Maybe the solution is to raise the pressure support even more, but I'm wondering if I'll be able to tolerate something over 8 for the entire night. I do have the V-COM device, which I could maybe use to slow down the inspiratory flow, so maybe that's a good option for me. But I'm also thinking about ASV because maybe what I need is something that adjusts the pressure support dynamically throughout the night so that I'm not getting pressure support of like 10+ early in the night when I don't need it. It seems that my nose closes up later in the night/early morning, possibly something to do with laying down for a long time and blood engorging my nasal blood vessels or something like that. For the earlier part of the night, I don't really know if there's something I can do.
Doctors have suggested some medication to lower my arousal threshold, like Quviviq, so I'm considering something like that. But at the same time, I would prefer to try to find a solution with the machine and avoid drugs. I also know that there are potential other solutions long-term re: my nasal breathing, but I've already tried many of them like steroid nasal sprays and saline rinses and allergy nasal sprays. I also had a turbinate reduction and deviated septum repair in May of 2025. I can breathe through my nose during the day now, but still have these issues at night. I have not really found much relief from any medications/sprays. I'm open to trying them again in the future, but I'm trying to be stepwise about this and focus on the PAP therapy first and see if I can get as much as I can out of that before making other changes.
I should note that in the last two nights when I've been using higher pressure support, I've woken up feeling better than I have in the recent past. But I still don't feel very good, so I don't want to give the impression that it's kind of been resolved. But at the same time, I have to note that the higher pressure support is definitely doing something. The question is, how much higher can I go without blowing myself up? And is that really the solution? Maybe a slightly higher EPAP might help stabilize things?
My hope is that people can look at my waveform data and help me understand what I'm looking at. It's just very confusing to me, these sort of frequent ragged breaths that I see and the waxing/waning breathing pattern. I just don't really understand what's causing this and what it all means and how to resolve it. I have been operating under the assumption that if I resolved the flat-top breaths that this would take care of itself, but it doesn't appear to have happened.
Maybe I have loop gain? I don't really understand it completely, but I've been reading a bit more about it recently and it seems to maybe match what is going on with me.
By the way, I don't think the cluster of OAs I had were real OAs. I think I was awake during that time.
I'm attaching main screenshot from OSCAR. Zoomed in images here:
https://imgur.com/a/FRjRvgf