Is EPR on a CPAP machine the same as PS on a BiPAP?

I should add "up to 3cms" I suppose, since that seems to be the max amount of EPR on the machines I'm familiar with.

In a recent thread Pugsy wrote (in reference to EPR) "…yes, this would in theory be the same with Pressure support on the bilevel machines…because that is what EPR really does…it's just pressure support up to 3."

My reason for asking is that I'm in the market for a travel machine, but have only seen them in straight CPAP with EPR up to 3. My current BiPap pressures are 11/7, so I would think that if I'm fine with a PS of 4 that I could probably get by with 3 OK as well.

But our hosts at CPAP.com have assured me that in fact the two things are totally different, and therefore my theory wouldn't work at all. I suppose I could change my PR 760P to CPAP mode with an EPR of 3 and try it for a night or two to see what happens.

Any thoughts would be appreciated.

EPR is only available on the ResMed machine.

old dude wrote: I suppose I could change my PR 760P to CPAP mode with an EPR of 3 and try it for a night or two to see what happens.

Just to be clear...you would have only BiFlex exhale relief in CPAP mode....EPR and BiFlex are two different animals.
Both are forms of exhale relief but they are totally different in how they go about it.
BiFlex at 3 is totally difference from EPR at 3.

EPR is not exactly like pressure support on bilevel machines but it is so close most people can't tell the difference.
And it is going to work pretty much like pressure support within that 3 cm limitation. Close enough that we call it a poor man's bilevel.

If you want to test out how EPR at 3 would feel.
Don't use CPAP mode....use fixed bilevel mode with IPAP 3 cm more than EPAP. so 7 EPAP and 10 IPAP.

old dude wrote:for a travel machine, but have only seen them in straight CPAP with EPR up to 3.

THinking about one of those tiny machines?? Do you want tiny machine or just another machine??
They don't have EPR either...I have no idea how their exhale relief functions.
It for sure isn't going to function like EPR...now it might be similar to EPR or pressure support where there is an abrupt reduction or it might be something totally different.

So...the short version...not all exhale relief functions on all the brands are identical to EPR in ResMed in that they simply drop the pressure on exhale. EPR is unique to ResMed.
Pressure support on the bilevel machines is very, very similar to EPR. Not the same totally but close enough that I bet I could test you with both and if you didn't know which machine..you wouldn't be able to feel much difference....
I test a S9 in CPAP mod with EPR at 3 and in bilevel mode with PS of 3....I thought I might..stress the might..have felt a difference but it was tiny.

If you are wanting one of those tiny travel machines....change your machine to straight cpap with no BiFlex...see if you can tolerate it.

Pugsy, yes, I was thinking about one of those tiny travel machines. I have a second 760P but I get tired of hauling both machines (one as a backup) on an 800 mile round trip every month to my other house. I thought I'd just leave one at each house and carry the small machine as a backup.

Let me digest your suggestions a bit, get out my notes and play with my machines some and see if I can generate an intelligent question or two when I get stuck. All the terminology can be a bit overwhelming if you don't reference it often.

Okay, if you are wanting one of those tiny machines.
Set your machine to cpap mode with a single pressure and no BiFlex.
Try 9 or 10 cm straight cpap...

We have nothing that will compare with the exhale relief features on those tiny machines...best thing would be to see if you can do okay with straight cpap and if you do then you know that whatever those machines do...you will most likely be okay with them. Worst case scenario thing.

There's simply no way to compare the tiny machine's exhale relief with what you have.
I at first thought you might be wanting a S9 Elite for backup but then thought it sounded like you wanted one of those tiny machines.
That's why I explained EPR so much....

So....If you can do straight cpap with out any form of exhale relief would be the closest thing you could try to see if you could get by with one of those tiny machines.
How they do any exhale relief....it isn't real clear in the literature and I don't know how to tell you how it might compare to what you are using now.

Pugsy wrote:Okay, if you are wanting one of those tiny machines.
Set your machine to cpap mode with a single pressure and no BiFlex.
Try 9 or 10 cm straight cpap...

We have nothing that will compare with the exhale relief features on those tiny machines...best thing would be to see if you can do okay with straight cpap and if you do then you know that whatever those machines do...you will most likely be okay with them. Worst case scenario thing.

There's simply no way to compare the tiny machine's exhale relief with what you have.
I at first thought you might be wanting a S9 Elite for backup but then thought it sounded like you wanted one of those tiny machines.
That's why I explained EPR so much....

So....If you can do straight cpap with out any form of exhale relief would be the closest thing you could try to see if you could get by with one of those tiny machines.
How they do any exhale relief....it isn't real clear in the literature and I don't know how to tell you how it might compare to what you are using now.

That's a good thought and a good plan of action Pugsy.

As you know, my original Rx was for 17/13, and I slowly worked it down on my own from there in baby steps. First, 15/11 then 13/9 and then down to my current levels of 11/7. Since I'm fine with EPAP pressures of 11 and 9 I would think I should be able to tolerate ~ 10 OK as well. I'll try it and report in when I get a chance.

Thanks!

Just as a note on EPR (and CFlex) is that these do NOT provide support. Essentially the machine allows the pressure to drop upto 3cm H2O, but does NOT support your breathing at that level. If the algorithim allowed the pressure to continue to fall, it would continue to fall. A BiLevel machine actually starts with an EPAP pressure where full support is provided, then increases to the IPAP pressure by adding additional Pressure Support (PS). BiFlex on Respironics machines and EPR on the Resmed machines allow a smoother transition from one pressure to the next. But the fundamental difference remains. A BiLevel machine supports the pressure, a CPAP with EPR just allows the pressure to fall, but does not support the breath.

JohnBFisher wrote:Just as a note on EPR (and CFlex) is that these do NOT provide support. Essentially the machine allows the pressure to drop upto 3cm H2O, but does NOT support your breathing at that level. If the algorithim allowed the pressure to continue to fall, it would continue to fall. A BiLevel machine actually starts with an EPAP pressure where full support is provided, then increases to the IPAP pressure by adding additional Pressure Support (PS). BiFlex on Respironics machines and EPR on the Resmed machines allow a smoother transition from one pressure to the next. But the fundamental difference remains. A BiLevel machine supports the pressure, a CPAP with EPR just allows the pressure to fall, but does not support the breath.

John, if you could explain this to me in more layman's terms I would appreciate it.

What would be the difference in actual therapy received, and what might be the difference in breathing perception to the patient?

JohnBFisher wrote:Just as a note on EPR (and CFlex) is that these do NOT provide support.

I would argue that EPR can (at least the last time I looked at it) provide Pressure Support.

Using independent flow and pressure transducers, this subject was breathing at CPAP 10.0 cmH2O EPR 3. Flow is superimposed on pressure. Clearly, the subject is inhaling at pressure 7.0 cmH2O, thus effectively on PS = 3.0 or BiPAP 10/7 (sorry for faint values on pressure grid, this version of the software package could not edit that):

Sludge wrote:

JohnBFisher wrote:Just as a note on EPR (and CFlex) is that these do NOT provide support.

I would argue that EPR can (at least the last time I looked at it) provide Pressure Support. ...

Sludge, you provide fairly convincing evidence. Previous graphs showed that it did not floor out at the reduced level, but it clearly does. So, the difference is nada ... other than the fact that a BiLevel machine can and generally does have a higher PS value than EPR can provide.