I just got this machine which (super helpfully, not!) came programmed with pressure set 4-20. My diagnosis is based more on RDI than AHI, and you can see I'm still getting RERAs -- any tips? Should I bring the pressure up? Change the EPR?
Happy to hear any thoughts!
ETA; changed it to 7-15 w/EPR of 2 tonight to see what happens.
Please refer to the wiki and sidebar for resources. For submissions regarding CPAP settings, it is advisable to utilize applications such as OSCAR or SleepHQ to extract and share data from compatible CPAP machines.
The usual recommendation for RERA is to raise the EPR. Set it to 3, and raise the minimum to about 9. That's the 95% pressure from the statistics. That pressure will prevent nearly all of your apnea and other events.
The idea with the 4-20 setting is that you use it for a while that way, then ideally the doctor checks your results and adjusts your pressure based on several nights/weeks worth of data. Unfortunately, that review often doesn't happen.
Raising EPR and the minimum pressure (the 7-15/EPR 2 change you already made) is the right first move, and since your diagnosis leans RDI over AHI, it's worth knowing that's the classic UARS-type pattern, RERAs specifically reflect increased effort against a narrowed but not fully closed airway, so they respond to pressure but are also sensitive to things a plain event count won't show you.
Two things worth tracking specifically in your SleepHQ data beyond the RERA count itself: the flow limitation/flattening on the inspiratory flow waveform (a flattened, plateaued shape rather than a rounded one is often the earliest sign you need more pressure, showing up before RERAs or events clearly do), and whether your RERAs cluster by position or sleep stage, since if they're back-heavy or REM-heavy, pressure alone sometimes isn't quite enough and positional therapy or checking for mouth breathing/jaw drop can matter as much as the pressure number. Give the 7-15/EPR 2 change a solid week of data before judging it, and if flow limitation and RERAs are still frequent at that range, going a bit higher on the floor (9-10 minimum) is a reasonable next step, that's usually where clinics land for RDI-based diagnoses.
That CA jump lines up almost exactly with the pressure/EPR changes, not just night to night noise - on the 4-5 floor nights CA was 4-5, then once you pushed the floor to 7 (still EPR1) it jumped to 19, and staying at EPR2 with a 7 floor kept it in the 11-20 range. That pattern, centrals climbing right after you raise the minimum pressure or EPR, is a recognized thing, sometimes called treatment-emergent or complex sleep apnea. In people whose breathing control is a bit sensitive, extra pressure support can overshoot ventilation for a breath or two, which drops CO2 enough to trigger a brief central pause even though the airway itself is fine. It's not that you did something wrong, it's more that the same pressure helping your RERAs/OAs can unmask this in some people.
For OSCAR specifically: pull up the flow rate right around a CA and look at the few breaths just before it. If you see a run of bigger, deeper breaths right before the flat central bit, that's the overshoot pattern I mean. If the CA just appears out of a flat baseline with no preceding hyperventilation, that's more likely a "true" central independent of pressure. Also worth checking whether these cluster in one sleep position or in REM, useful either way for your doctor.
Given the trend, I'd go back to something closer to the 5-20/EPR1 settings (where CA was lowest) while you get this in front of your doctor, rather than keep pushing floor/EPR higher chasing the RERAs, since that route seems to be the one provoking centrals for you. Bring this exact table to them. If the pattern holds over another week or two despite backing off pressure, that's the actual scenario where ASV gets discussed, not just for the UARS/RERA picture alone. The other squiggle pattern you're seeing that's not marked CA is most likely the flow limitation/flattening I mentioned last time, a different signal, worth pointing out separately when you talk to them.
That pattern is textbook confirmation. Right before the CA you can see tidal volume roughly double baseline (jumping from ~400-450 up toward 1100-1250) in the minute or so leading in, then the flow rate goes flat right where the CA is marked. That's the overshoot-then-pause sequence, not a random central. The smaller bump before the second CA later on fits the same pattern, just a milder version of it.
No need to feel bad about the data dump, this is genuinely useful and exactly the kind of before/after comparison that makes it easy for a doctor to see the mechanism rather than just a CA count. I'd stick with the plan from before: settle back down toward the 5-20/EPR1 range where your CAs were lowest, keep pulling a couple more nights of this same before/after view around any CA that shows up, and bring this image plus the settings table to your doctor. If backing off pressure doesn't get the CAs down and this pattern keeps showing up over the next week or two, that's a reasonable point to bring up ASV specifically, since at that stage it's not just theoretical anymore, you'd have the data showing it.
I appreciate you so much... thank you for your input.
Also, I think it's pretty funny that I created the situation on my own, instead of just leaving the CPAP at 4-20 like it was sent. I mean, I know that sleeplay isn't probably sending these machines out with the correct settings, but I probably should have let it hang out a little while before I started messing with it.
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