BiFlex question

krousseau · Post by **krousseau** » Tue Dec 11, 2007 9:00 am

Why does a BiPAP need BiFlex?

Guest · Post by **Guest** » Tue Dec 11, 2007 10:07 am

why does a CPAP need C-Flex??
It's for patient comfort. The A-Flex actually follows a lot of the same logic as the Bi-Flex.
All you need to do is breathe on a Flex-enabled unit to feel the difference.

krousseau · Post by **krousseau** » Tue Dec 11, 2007 11:08 am

Well-with CPAP there is a constant pressure for inhalation and exhalation. Adding CFlex gives you a drop in pressure with exhalation. I do breathe on a flex enabled machine-set at the max-I understand me (or anyone) on CPAP needing CFlex.

The question is why does BiPAP need CFlex? With BiPAP you already have a lower pressure for exhalation-so what is the purpose of adding the flex feature.

Guest · Post by **Guest** » Tue Dec 11, 2007 11:53 am

biflex.respironics.com

Bi-Flex softens the pressure delivery - refer to the graphic and explanation.

krousseau · Post by **krousseau** » Tue Dec 11, 2007 12:20 pm

Thanks for the great link. I've been to Respironics but haven't delved into the site that much. Recent decines in treatment are leading to trying to find more info.
A "softening" or bluting of pressure changes is what I have been thinking in regard to BiPAP. A sudden change in pressure from high to low seems like it alone might feel strange and disrupt sleep. Am debating about paying out of pocket for a BiPAP as I'm pretty sure I would not meet Medicare or insurance guidelines.

Guest · Post by **Guest** » Tue Dec 11, 2007 12:50 pm

what is your pressure now?
Usually BiPAP is for users that can't tolerate normal CPAP as well as pressures over 13-ish.

krousseau · Post by **krousseau** » Tue Dec 11, 2007 1:12 pm

I have been trying to re-tweak my pressure. Last night decided to start all over and reset the machine at 8-14; that is the range Rx'd when I got my auto pap. With weight loss and CBT I was using less pressure, less aerophagia, insomnia improved, and tapered off ambien. RDI is good-treatment looks like a success--only change is number is no more zero's-RDI is still well below 5-often 2-3-mostly 3-4. For about 5 weeks insomnia returned, aerophagia back worse than ever, back to Ambien every night, and "anxious" again. I hate to tell the doc about anxiety-I've been around health care long enough to know how women with anxiety get treated-I'm not going there.

rested gal · Post by **rested gal** » Tue Dec 11, 2007 2:12 pm

Bilevel machines don't "need" Bi-Flex, but it sure is a comfortable feature for many people. Respironics bilevels are the only ones that have it.

As I understand it, Bi-Flex softens the beginning of the already lower exhale pressure. It also smooths the transitions back and forth between the two pressures (EPAP/IPAP.)

I've used the Respironics bipaps with and without Bi-Flex turned on. For me, there is a very noticeable more "natural breathing" feeling when Bi-Flex is on. I've also used resmed bilevels (VPAP III) and missed the smoothness of Bi-Flex.

Kathy, I don't know why that is. You'd think that simply having a lower exhale pressure, as all bilevel machines do, would be enough comfort for breathing out. But after trying bilevel both ways, Bi-flex makes it feel smoother and more natural to breathe out. No feeling of resistance at all.

The beginning of breathing out against pressure is usually where most people notice resistance. To me, Bi-Flex adds "icing on the cake" comfort to the start of each exhalation, even at the lower EPAP pressure.

Bi-Flex also gives a smoother move up to the inhale pressure when I start to inhale. I suppose one could say Bi-Flex in the bipap and A-Flex in the autopap are very similar. Smoother, more natural feeling for many people. Not all people -- many.

A different kind of adjustable comfort feature that bilevel machines have is called "Rise Time" which governs how abruptly the full IPAP pressure will hit when you start to inhale. The Respironics bipaps have that, too, if a person prefers to not turn on Bi-Flex, but use a certain length of rise time instead. Can't use both at the same time. If Bi-flex is turned on, the "comfort rise" setting will not even appear on the menu. If Bi-flex is turned off, you can set a rise time if you wish.

After trying all the available rise time settings as well as all the Bi-Flex settings, Bi-Flex felt more comfortable to me. If I had to use a bilevel that didn't have Bi-Flex, I'd definitely want to set a long "rise time" for a less jolting change to the higher IPAP.

IMPORTANT NOTE:
I keep calling these things "comfort" settings, but for some people with serious underlying illnesses beyond just OSA, those adjustments could have an impact on the effectiveness of their treatment. In some cases, the rise time would need to be adjusted not for comfort, but for how their treatment actually needed to be delivered.

StillAnotherGuest (nicknamed sleepydave on another message board) brought that important point out (the links below.) What should be done with the "comfort" settings depends on what you're trying to treat and why a person is using a bilevel machine in the first place. I happen to be using it just for additional comfort. Even though my pressure is not high (straight 10 would treat me fine and I can breathe out against it fine) I simply like the way bilevel, and particularly bilevel with Bi-Flex, feels so very natural.

Two posts by sleepydave (who is "StillAnotherGuest" on the cpaptalk board) regarding the "rise time" setting:

Sun Oct 15, 2006 subject: On Rise Times &c
http://www.apneasupport.org/viewtopic.php?p=24770

Oct 14, 2006 subject: complex sleep apnea and BiPaP use.
viewtopic.php?t=14359