Auto bipap stuck in cpap mode for mo reason

Thank you!

But I'm still not sure what this pressure range means. So, if min PS was 4 and max PS was 6, does that mean the difference between my ipap and epap can only be 6?

Pressure support is the difference between EPAP and IPAP. Your machine has a setting that allows for the PS to vary if it needs to.
If you used 4 min and 6 max then the difference between EPAP and IPAP can never be less that the 4 minimum and never more than 6...it roams around as it senses the need to change. When you first start out the night it will be at the minimum though and won't change from the minimum until it senses a need.

Further example... EPAP say at 5.....max IPAP say at 20....PS of 4 min and 6 max.
The machine has a big range to wander around in.
The night would start with EPAP of 5 and IPAP of 9 (that PS of 4) and as the night progresses if the airway starts to collapse the machine will sense it and respond with either more EPAP or more IPAP and when more EPAP is given then that drives up IPAP and when more IPAP is given then that drags EPAP up with it but the difference between them will always be the 4 to 6 range. It might decide it only needs 4 PS all night now matter how much the EPAP and IPAP wants to move around.
You can also set PS so that it never varies...just set minimum and maximum PS to the same setting...like 4

If the machine ended up sensing you needed say 12 EPAP then IPAP would be 16 with PS of 4

Thanks, I appreciate that.

All this started because I thought by reducing the Max IPAP number, the machine wouldn't have to roam around in such a big area. But I didn't even realize that the Max PS number would essentially do the same thing.

Last night I had Min PS 4 and Max PS 6. My AHI was 20 so tonight I'll bring Max PS down to 5.

PS is more for comfort and not AHI. Changing your max PS is unlikely to do anything...heck for all we know that max of 6 may never have been reached anyway.

If your AHI is too high we need to look at
1. what type of events you are having
2. then look at most likely EPAP starting point.

In general when dealing with obstructive in nature events (OAs and hyponeas) we look at EPAP for OA and IPAP for hyponeas and if we see a large number of Clear airway events we have a different discussion.

If you are seeing a large number of OAs and/or hyponeas then I suspect that EPAP is the first thing that would need to be looked at and changed. EPAP is what holds the airway open as a baseline setting....starting point if you want to think of it that way and any changes when in auto adjusting mode have to start there. If EPAP is too low then the machine can't respond quickly enough to prevent the OAs and hyponeas. Prevent them better and the machine can do its job better.

At this point, all I want to do is get back to the settings I had before. Take a look at the screenshots below--from two nights a couple months ago, with the original settings.

Would this mean I should set Min PS to 0 and Max PS to 5?





I browsed through a dozen or so nights, and the Max PS number NEVER went above five. (Sometimes it was 4.50 or 4.60.)

Yes, it would appear that PS minimum was 0 if the statistics from SleepyHead are to be believed.
We could verify by using Encore if you wish but EPAP min and IPAP max is 4 and that would be what we would expect to see if PS min was 0.
And yes then it appears that PS max was 5.

I don't know what your AHI was running back then but if it was higher than you want to see my advice about what to do about the AHI still stands. PS isn't the problem and setting it to 0 is unlikely to fix things.
PS isn't used in that capacity.