(06-07-2014 05:41 PM)zonk Wrote: EPR useful or useless
Answer is: It depends on the person
Some people have no problems exhaling against the full positive air pressure of their prescription. Others do. Why some people have trouble and others don't seems to be a mystery. For some people, like retired_guy, there may be another medical condition that explains or contributes to the difficulty. For others, like me, there really doesn't seem to be an explanation.
EPR (or C-Flex+ or A-Flex) can be also be a useful tool in helping some people conquer aerophagia. (And yet, for others, EPR or Flex simply adds to the misery of aerophagia.)
So for some PAPers, EPR or Flex is a critical tool for being able to breathe comfortably with the machine all night long. For others, it really is pretty much useless.
But since you can always turn a feature that you don't need OFF and you can't turn something that is not available ON, I think it's important that all machines have some form of EPR. And so I don't think it's a marketing ploy. Rather I really do see it as a feature designed to help improve compliance amongst the folks who have trouble becoming compliant because they have trouble fully exhaling against the positive air pressure.
Quote:Regardless what manufacturers call their own brand of pressure relief feature and some fancy description 'natural breathing experience', EPR works on the principle lowering the pressure on exhale, might sound nice on paper but in fact lowering pressure have a negative effect
The negative effect of EPR on most people's therapy
is negligible; for most people, the airway does not become drastically more likely to collapse just because EPR has been turned on. And the comfort level for some people improves dramatically with EPR. And as comfort goes up, so does compliance.
And if you're in the minority of people who both like EPR and who find that the AHI does increase when EPR is turned on, there's an obvious solution: Increase the pressure setting by the EPR setting. You see, its the perceived drop
in the pressure that makes it easier to exhale for many of us. In other words there are folks who will find it easier to fully exhale if the pressure is set to 12 with EPR = 3 so the EPAP = 9 rather than simply having a fixed pressure of 9 throughout the entire breath cycle. I know that may sound strange to those of you who find EPR useless, but a drop
in pressure does make exhaling against the pressure easier.
Quote:IMO, we should have one machine does the following and data capable too (no bricks please)
constant pressure, apap, bilevel, and auto bilevel
Actually such machines DO exist and they're called the S9 VPAP Auto and the PR System One Series 60 BiPAP Auto.
Both of these auto bilevels have modes for CPAP, bilevel, and auto bilevel. While technically neither has an APAP mode, both the S9 VPAP Auto and the PR System One Series 60 BiPAP Auto can have the auto bilevel settings set in such a way to make the machine run in APAP mode:
On the VPAP all you have to do is set PS = 0, and then you've got an Auto Set (with no EPR) running in the range min EPAP to max IPAP. If you want to mimic an Auto Set with EPR = 1, 2, or 3, then you use VPAP Auto mode with the PS = 1, 2, or 3.
On the System One Series 60 all you have to do is set min PS = max PS = 0, and then you've got you've got a System One Series 60 Auto PAP (with Bi-Flex acting as A-Flex) running in the range min EPAP to max IPAP.
So the problem is not that these machines don't exist. The problems are (1) the billing code for the VPAP Auto and BiPAP Auto is NOT the same as the billing code for CPAP/APAP and (2) the cost of a VPAP Auto and BiPAP Auto is about twice the cost of the APAP in the same line.
And of course, the VPAP Auto and BiPAP Auto don't do all the fancy (and expensive) stuff the ASV machines do. But that's another whole kettle of worms.