A-flex Trying to Self Breathe?

FreeLancer74 wrote:Maybe I'm thinking about it too much so it stays out of sync while I'm awake. I figured the machine would wait for me to exhale before it would try and change the pressure.

That was the mistake I made the first couple of nights I used a machine with C-flex. I, too, expected C-flex to hold the pressure down until I was ready to inhale again. Doesn't work like that. Nor does A-flex. Those features are designed to let the "regular" pressure come back in before our exhalation is completely finished.

At high pressures and with a not-very-forceful natural exhalation, the regular pressure can come back in almost immediately after the drop at the beginning of breathing out. As soon as the machine senses any waning of the force of our exhalation, the regular pressure is supposed to start coming back in...even if we are far from finished exhaling.

The first time I used C-flex and kept feeling the pressure come back in before I was anywhere near through exhaling, I thought the machine was broken. I kept trying to take another breath to "get in synch" with what the machine was doing. That was like a dog chasing its tail, because you can never make your breathing in and out match the feel of what the pressure is doing. It was only after I contacted -SWS and asked him about it, that I found out that was the way it was supposed to work....bringing in the regular pressure before exhalation was finished. After that, I relaxed, quit noticing the pressure change, and enjoyed the feeling of breathing out more easily.

A few people never can get used to that feeling of pressure coming in before the exhalation is finished. If they can't, it can turn into breath stacking like WillSucceed experienced when his body kept making his breathing try to keep up with what C-Flex was doing, to the point of waking up panting.

The only machines that keep the pressure down "forever"...all the way throughout exhaling and even if you pause after exhaling... keeping the pressure down all the time until YOU start to take a breath again are bi-level and bi-level auto machines.

All that said, C-flex and A-flex can be very comfortable once a person stops thinking about what they are doing and just breathes naturally. Experiment with the different settings. Find one you like, or even turn 'em off if that feels better. It's all about comfort and what works best for you.

Freelancer74,

This is an old thread, but I am a new cpap user.

I had exactly the same problem you described in the opening msg of this thread!! Now after reading the entire thread, I have a feeling the problem may be significantly influenced by personal perferences. My starting is 4. A closer reading of the spec says the APAP starts working only at 6+ !! So I had no relief 4 - 6.

Even at higher pressures of 10, I simply could not tolerate the Aflex fighting me when I wanted to take a long breath while I was awake. After trying Aflex for 2 weeks, now I am on Cflex, and for me there is a world of difference for the better.

Lancer writes that the AFLEX patters seems screwed up, and doesn't match his breathing pattern.

I sometimes notice the same thing, just when I don the mask, and wait for the machine to roar to life. The machine is wanting me to inhale when I clearly want to exhale...sort of a po-TAY-to/po-TAH-to thing.

I let the machine win these little spats (it's a long night.) Once I adjust my pattern, I'm a "goner" in seconds anyway.

Regard all - - Tom

Anonymous wrote:remember, A-Flex really doesn't start to "work" and get into the groove until it's in the Auto Mode and has began searching for its critical and optimal ranges...
see sleepapnea.respironics.com/technology/autoalgorithm.aspx

An old thread revisited about adjusting to AFlex lead me to this Respironics link about their Algorithm. I don't know why I hadn't seen it before but it gives a pretty good explanation of how the features are supposed to work. I recommend new Auto M users to read it so they know what's going on.

OldLincoln, Thank you for posting that link!

only have cflex . since bumping my min pressure up to 8.5, when first startup i find it a little harder to relax and get in sync with the pressure, ipap & epap so i hit the ramp for 10min at 5 & it seems much easier to settle down.... wouldn't mind trying a bipap auto just to see if it wouldn't be better therapy ?