[Pressure] Pressure gets lower over time?

[peter e]

Hi!

New here.

Struggling with my ResMed Lumis 100 VPAP ST....

Using it in ST mode (Might also be called "bi-level", I think?).
Been fiddling with the pressure settings, currently they're at
EPAP 13
IPAP 18
(Don't know the unit... language is set to Swedish, if that matters.)

The problem:
I thought these settings would mean it switches between a fixed low pressure and a fixed high pressure? But after using it for a short while (minutes) I get the feeling its high pressure starts to drop. After a while it feels like I barely get any breathing support at all.

I have already had the machine swapped once, the nurse said this one was brand new, but the problem remains... so I don't think it's a mechanical problem anymore... perhaps a setting somewhere that I've overlooked?

I'm fairly new to being supercharged, so I probably have a thing or two to learn........

Thanks!

[Crimson Nape]

Hi peter e -
There are two different units of measure for pressure on the Resmed.  Your numbers would seen to indicate that your machine is using centimeters H₂O.  Commonly written here as 13cm or 18cm.  Your questions about settings and your problem will need to be answered by someone familiar with your CPAP model.

[jaswilliams]

I suspect pressure is not dropping it is more likely you are getting used to it I don’t know if the machine is supported by sleepyhead or just resscan, either way the graphs will show us what is happening.

[gwc2795]

The ResMed Lumis 100 VPAP ST is is a noninvasive ventilator designed for spontaneously breathing. It has both a ramp up and ramp down function. I wonder if the ramp up is on and set to 4, this could produce the effect.

[peter e]

Jaswilliams:
I've considered it, and I do have some self doubt, but... I actually don't think I'm imagining it.
In the beginning it's a very distinct feeling, each intake push fairly hard on the seal, since I have raised the IPAP level in an attempt to get more air, I think it was 16 (cm?) to begin with.
But after a rather short amount of time (minutes) I feel that the push against my face is much lower AND I feel like I don't get enough air. If I intentionally take deep breaths, I still get air (it's still a positive pressure after all) but when I try to relax, try to sleep, my breaths seem to get shallower and shallower.
I'd buy "getting used to it" if it had been an hour or more, but not after just a few minutes.

gwc2795:
Ramp is turned off. (Both of them.)
Ramp up was activated in the beginning but I disabled that too rather soon.
It seems easier to me to fit the mask properly if I have full pressure from the beginning. With Ramp it might start to leak when pressure rises, if I haven't gotten the mask in the proper position.
And yes, I've had some problems finding a mask with a good fit... but as long as I don't move around too much in my sleep, this one does the job.
(The leak report thingie in the morning is always green = ok, at least.)

[peter e]

Oh, and I got the clinical manual today, but couldn't find any settings that might cause this phenomenon. (Nothing that ins't already deactivated, at least...)
Then again, my English skills aren't perfect so I may have missed something.