A-FLEX or C-FLEX??

I really did search. And I really could not find a clear description of the difference between A-flex and C-flex on the Remstar M-Series Auto. Can anyone clearly describe the differences? And how would one decide among the 4 combinations of APAP with A-flex; APAP with C-flex, CPAP with A-flex or CPAP with C-flex? Sorry if this is actually in the archives, but I didn't find it.

Sorry ,I can't tell the difference and after many ,many months of trial and error have settled on neither and use straight cpap as I was titrated.

plr66 wrote:I really did search. And I really could not find a clear description of the difference between A-flex and C-flex on the Remstar M-Series Auto. Can anyone clearly describe the differences? And how would one decide among the 4 combinations of APAP with A-flex; APAP with C-flex, CPAP with A-flex or CPAP with C-flex? Sorry if this is actually in the archives, but I didn't find it.

Get AFLEX and you GET CFLEX as well, which mode you use is your preference. AFLEX offers the most relief "comfort".

AFLEX works on both Inhale and Exhale with the Exhale portion being CFLEX.
CFLEX works only on Exhale, does nothing to the Inhale.


AFLEX works by softening the square sharp peaks found in inhale pressure, it rounds off the square corners so inhale feels more natural.

CFLEX works by momentarily reducing the Exhale pressure at the beginning, then it ramps up during that exhale to the splint pressure.

Both are comfort settings and make breathing against the pressure easier. Biggest mistake most people make is setting either one on their Maximum setting of 3 then it can become uncomfortable. I suggest you try #2 setting for a while then you can experiment going up/down from there to see if you prefer the other.

I found that use of AFLEX my pre-CPAP symptoms slowly returned (using #3), so I switched it to CFLEX and lost a bit of comfort but feel more refreshed from sleep if there is such a thing.

AFLEX is also explained in a graph here:
http://aflex.respironics.com/

The peaks are Inhale, the colored lines are the relief offered by each setting.

CFLEX the other option is shown in the graph here, you will notice CFLEX only works on the exhale portion of the breath, AFLEX works on both.

http://cflex.respironics.com/

If you have a Bipap, you have BIFLEX:
http://bflex.respironics.com/

Thanks so much, Snoredog. Your post is so helpful!

In a nutshell.... C-flex drops pressure some at the beginning of your exhalation. C-flex lets the regular pressure back in before you've finished exhaling. C-Flex operates only at (and during) the first part of the exhalation.

A-Flex does what C-flex does -- dropping the pressure at the beginning of your exhalation. But instead of letting the regular pressure back in abruptly as the exhalation begins to dwindle, A-flex smooths out the transition of pressure coming back in. A-flex rounds out the transitions during both exhaling and inhaling. Feels smoother to many people.

Neither C-Flex nor A-Flex drop the pressure a specific number of cm's. The drop in pressure at the beginning of exhalation that either of those features gives is dependent on how forcefully a person breathes out. A strong huffing start to the exhalation will drop the pressure more than breathing out lightly does.

Thanks, RG. So both A-flex and C-flex are for comfort. Do these flex settings also function as tools that are used to affect AI, OA, HI episodes? And if so, how does one decide what's indicated, aside from trial and error?

I tried both A Flex and C Flex. A Flex was very comfortable for breathing but something about it just didn't feel right. The only way I can describe it is to say my lungs were empty. I didn't sleep well at all with it so I went back to C Flex. It works better for me. YMMV

plr66 wrote:Thanks, RG. So both A-flex and C-flex are for comfort. Do these flex settings also function as tools that are used to affect AI, OA, HI episodes? And if so, how does one decide what's indicated, aside from trial and error?

They are primarily comfort features. They aren't there as tools to affect events. Many people do find that their treatment in general goes better if exhaling against pressure is made a little easier.

Some don't find those features comfortable. Some find them to be counterproductive to their treatment.

Trying a comfort feature is the only way to see if it actually feels comfortable. Having software to monitor one's own treatment is the way to see if treatment with a comfort feature turned on is going well.