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+--- Thread: [Pressure] CPAP Pressure, CA's, and elevation (/Thread-Pressure-CPAP-Pressure-CA-s-and-elevation)
CPAP Pressure, CA's, and elevation - GuyScharf - 11-02-2023
My SIL is visiting us. She has a VAuto that she has used for 6 months. Settings were PS 6 over 8.0-25.0. She was prescribed this machine to treat snoring and breathing pauses noticed by others. AHI at our house has been above 3.0, almost entirely CA's. Looking back at her home, the AHI's were a little more mixed but predominantly CA's. Snoring is now infrequent and only for a short duration--successfully treated in my opinion.
We don't have access to the lab study or know why the machine was set to these settings.
As an aside, she was using a F20 mask with small cushion, and the cushion was clearly too small and hurting her nose. We tried a medium cushion, but there were too many leaks. Also tried a F30 and an Amara View but those had leak problems as well, at least with the cushions I had on hand. Finally settled on an Simplus with small cushion (same as used in her lab sleep study), and it is working well with no leaks.
I titrated pressure down over several days and machine is now set at PS 4 over 8.0-15.0. AHI for the last two nights has been 0.5 or less, still mostly CA's. With these lower settings, statistics like flow limit, snoring, OA, H, etc. remain good and have apparently not been affected by reducing the pressure. I think I will try reducing the pressure further to see if she even needs this much pressure. I have at most 6 more nights in which I can adjust machine settings easily.
My elevation question is this: her home has an elevation of about 30 ft; we are at 2800 ft. My concern is if we dial in the pressure to a good setting at 2800 ft, what changes might be expected at a 30 ft elevation?
Thanks for any advice.
RE: CPAP Pressure, CA's, and elevation - SarcasticDave94 - 11-02-2023
The higher PS if not really needed can cause the CA to go up in some. As you'll know, higher PS in this case probably increased CO2 flushing and voila more CA.
From here on a VAuto I think you'll have a trigger setting that can be changed to higher if necessary in CA combat.
Elevation with those ranges, I'm not thinking it'll be a big issue.
RE: CPAP Pressure, CA's, and elevation - gainerfull - 11-03-2023
EPAP controls obstructive events
IPAP controls hypopnea, snoring, RERA
Sounds like you'll want to change trigger to "high" or "very high" to solve the Centrals.