Why does EPR help flow limitation?

[Stubert]

Hi,

I cannot understand how EPR can possible help on flow limitations, as it would be logical just to increase pressure to avoid obstruction, which causes flow limitation, which leads to RERA/arousal and possible central apneas?

I do not get it, as flow limitation occurs on end of inhale?, but EPR is on exhale..

I have attached an example of my typical flow limitation, from a few nights ago, please correct me if I do not understand flow limitation correctly?

[Gideon]

Yes that is logical but think of your Prisma, or any CPAP/APAP as a BiLevel machine.
EPAP is the basis for splinting open the airway, to treat/minimize OA events, and that is why CPAPs were invented first. Now read any BiLevel Titration protocol. IPAP is increased to treat partial obstructions called hypopneas. Flow Limitations may be thought of as a form of untimed hypopneas. This difference in pressure on bilevels is called Pressure Support or PS. It effectively treats flow limits, and since flow limits are integral to RERAS, by eliminating the flow limits you treat the RERAS.
You asked why this works, I don't know the mechanism, but it does.

Back to your Prisma, or a a ResMed,
On these machines, CPAPs, EPR is defined as a comfort feature and as a comfort feature this "cannot" have a therapeutic effect so the manufacturers never take about it. Com}are the flow rate curve of a BiLevel with PS=EPR and EPAP matching on both machines (EPAP=Pressure-EPR) and you will find the curves are identical.

[Stubert]

Thanks, trying to understand :-).

Do you think a setting of EPR 1, could make a differrence, in my attached chart?

If I set EPR 1, I will raise min. from 10-11 and max from 13.5-14.5.

I cannot deal with EPR 2, as my Airtouch F20 mask is moving to much in and out, due to pressure change and makes it to uncomfortable.

In overall I do not have that many breaths, during the night, where top of "breath" is flat or spiked form, only when obstruction gets tough.

I am waiting like crazy to OSCAR can support my Prisma MAX, so I can have a flow limit chart.