Need some advice on APAP Range settings

[palerider]

The DreamStations have Flex which I think is EPR with a less clear name:

it's not. it doesn't behave the same way, and the numbers don't correspond.

[vsheline]

The DreamStations have Flex which I think is EPR with a less clear name: "This allows you to adjust the level of air pressure relief that you feel when you exhale during therapy. Your home care provider can enable or disable this feature when your provider enables flex a level will already be set for you on the device. You can increase or decrease the setting from 1 to 3. The setting of 1 provides a small amount of pressure relief with higher numbers providing additional relief."

Hi chill,

There are many threads where the differences between Philips Respironics Flex and ResMed EPR have been discussed.

They have the same purpose, and in our discussions we (or at least I) sometimes use the term "EPR" in the generic sense, meaning all types of exhalation pressure relief, including 'Flex.

In brief, all settings of A-Flex add 2 cmH2O of fixed pressure relief which starts when we begin exhaling and ends when inhalation starts, and settings of 1, 2 and 3 add increasingly more additional pressure reduction while we are actively exhaling, depending on how strongly we are exhaling.

The A-Flex settings 1, 2 and 3 also affect how early the pressure starts dropping toward the end of inhalation, while we are trying to finish the last little bit of our inhalation.

Unlike Flex, ResMed EPR is a fairly straightforward fixed reduction of 1, 2 or 3 cmH2O which starts when we begin exhaling and ends when we begin inhaling.

Take care,
--- Vaughn

[palerider]

In brief, all settings of A-Flex add 2 cmH2O of fixed pressure relief which starts when we begin exhaling and ends when inhalation starts, and settings of 1, 2 and 3 add even more pressure reduction while we are actively exhaling, depending on how strongly we are exhaling.

do you have any documentation on that? because what i've always read is that the *flex reduces pressure *up to* half a cm X the setting number, depending on how deeply one is breathing.

[vsheline]

what i've always read is that the *flex reduces pressure *up to* half a cm X the setting number, depending on how deeply one is breathing.

That would approximately describe the original C-Flex.

In addition to pressure relief based on (meaning, proportional to) the strength of the exhalation Flow, C-Flex+ (the Plus version) and A-Flex also add 2 cmH2O of fixed pressure relief which starts when exhalation starts and ends when inhalation starts.

[palerider]

what i've always read is that the *flex reduces pressure *up to* half a cm X the setting number, depending on how deeply one is breathing.

That would approximately describe the original C-Flex.

Both C-Flex+ and A-Flex add the 2 cmH2O of fixed pressure relief which starts when exhalation starts and ends when inhalation starts.

now, see, this video: https://www.youtube.com/watch?v=ZPX3OUuRzBY is consistent with what I'd heard, that the primary difference between cflex and aflex is that aflex gives more pressure smoothing as it changes the pressure between flex and non flex amounts.

but I suppose it'd take someone with a respironics machine and a manometer to find out for sure.... I've got the manometer, but no respir machines.

[vsheline]

but I suppose it'd take someone with a respironics machine and a manometer to find out for sure.... I've got the manometer, but no respir machines.

Phillips Respironics used to have figures for C-Flex+ and A-Flex on its various websites, but the websites have been redesigned in the past year or two, and a lot of the useful information has been dropped in favor of a more sales oriented presentation.

Here is an old Respironics brochure providing figures of the 'Flex family but does not include C-Flex+ (which behaves like A-Flex):
http://www.apneaboard.com/Respironics-CP...ochure.pdf

This earlier post contains a link to a paper which contains a figure showing how A-Flex affects the pressure:
http://www.apneaboard.com/forums/Thread-...#pid148574

This earlier post explains further:
http://www.apneaboard.com/forums/Thread-...#pid145923

[palerider]

you keep pointing back to other things you've said in the past, but other than a mention in that NIH paper, I've seen nothing to corroborate a 2+cm drop in pressure.

the way the NIH paper reads, the pressure drops as much as 2cm, at the start of exhale, then comes back up, nearly to regular pressure, which it resumes at the time of the next inhale.

[vsheline]

... other than a mention in that NIH paper, I've seen nothing to corroborate a 2+cm drop in pressure.

the way the NIH paper reads, the pressure drops as much as 2cm, at the start of exhale, then comes back up, nearly to regular pressure, which it resumes at the time of the next inhale.

The figures in the Respironics brochure corroborate the figure in the NIH paper.

The figure in the paper shows when inhalation starts the pressure returns to IPAP (increases 2 cmH2O).

The NIH paper says at the bottom right of its first page:
"Initially, pressure is significantly reduced at the start of exhalation, with the pressure approximately 2 cm H2O less than inspiratory pressure by the end of exhalation."

The paper is trying to say that the pressure is very much reduced at the beginning of exhalation (which is when the 2 cmH2O of fixed pressure relief is assisted by the Flow-based component of A-Flex), after which the pressure relief tapers off to 2 cmH2O by the end of exhalation (because the Flow-based component of A-Flex tapers off as our exhalation Flow tapers off to zero).

[palerider]

I suppose we'll have to just agree to disagree till someone comes up with a manometer and some empirical information

[green wings]

I'm just curious. If you want to check therapy pressure while someone is using the device, where does a manometer attach? I looked at a couple for sale on an online CPAP supplies site, but they looked like they would attach to the end of the hose where it normally attaches to the mask.