CPAP-BIPAP-APAP-BiLevel- Simple Differences

Can anyone give me a simple to the point description of what the various machines do?? I have CPAP but, having major aerophagia. I need a good argument for my doc as to which one would help.

Thanks
Debbie

Go to the top of this page and click on CPAP Wiki (lightbulb) then scroll down to (categories) on the right side of the page and you can click on APAP, BIPAP, or CPAP.

Without taking into account any kind of exhale relief or ramp/settling

CPAP - single constant pressure
APAP - single pressure moving between a lower number and a higher number
BiPAP/BiLevel (not Auto) - single inhale pressure and single exhale pressure (IPAP and EPAP)
Auto BiPAP/BiLevel (Respironics and Resmed do it slightly differently) - (Respironics) range of exhale pressures where the minimum is specified and range of inhale pressures where the maximum is specified. Max PS comes into play here determining what each of these should be.

CPAP and APAP machines fall under the same insurance code. In other words, a prescription for a CPAP will let you buy an APAP. Whether the DME will provide you with one and fill out the paperwork to get your insurance company to reimburse them for it, it another story altogether. In the titration study for a CPAP, the tech increases the one pressure level until (ideally) all apneas and hypopneas disappear in REM sleep on your back. If you get an APAP prescription, that titrated pressure is usually in the middle of the range. The top is often a couple of cm above the titrated pressure and the bottom is a couple of cm below.

Bi-level machines have a different insurance code and a prescription for a CPAP/APAP will NOT allow you to buy a bi-level machine. They require a prescription written for a bi-level machine. The PR bi-level machines are called BiPAPs. The Resmed bi-level machines are called VPAPs. Most insurance companies will require that you have "failed" CPAP before they will pay for a bi-level machine.

"Failing CPAP" means at a minimum that your doctor is willing to put in writing that he believes you have made an good faith effort to adjust to CPAP (i.e. have been compliant for some minimum period of time), but in spite of being compliant that you are having one or more medical problems adjusting to therapy. These problems can include:

• Therapy is not effective at titrated level and pressure changes have been made without making treatment become effective. "Effective" here usually means that your AHI remains above 5 in spite of CPAP or APAP treatment.
  
  Therapy is effective in terms of AHI, but daytime symptoms have not been resolved or have gotten worse. In other words, you're still experiencing problems with excessive daytime sleepiness and fatigue in spite of the fact that your AHI is under 5.0.
  
  Patient cannot tolerate serious side effects of CPAP AND multiple efforts to relieve those side effects have been made to no avail. Serious aereophagia counts as a serious side effect. But there also has to be some kind of multiple documented efforts to relieve those side effects. And those efforts have to have failed. These efforts have to have been made over the course of at least several weeks or maybe even months. Things such as changing the pressure setting, switching from a straight CPAP setting to an APAP range, and changing the mask style (from nasal to FFM or from nasal to nasal pillows for example) are all things that have to have been done and the doctor has to say they have been done. And that the patient has found no relief of the side effects.

Once your doctor has decided that you may need a bi-level machine (i.e. once he is willing to sign a letter of medical necessity to your insurance company so they will pay for it), he will then more than likely also order a bi-level titration sleep study. That's because a bi-level machine requires that two pressure settings---the IPAP and the EPAP---be determined in the lab instead of just one. The EPAP is increased when you when you have apneas and the IPAP is increased when you have hypopneas. [This is a simplfied version of what they do. They will also increase the IPAP for an apnea if the increase in EPAP winds up making EPAP=IPAP for example.]

Now from what I've read there seems to be two easily identifiable, but overlapping groups of people who wind up with bi-level machines on this forum who also happen to have rather run-of-the-mill OSA:

1) Folks with rather high pressure settings (like over 15, often like 18, 19, and 20) who have real trouble exhaling against their pressure even with the exhale relief on their CPAP/APAP set at its maximum level.

2) Folks with serious aerophagia problems who seem to need low exhale pressure that stays low for the entire exhale portion of the breath---which doesn't exactly happen with exhale relief. There's an interesting bunch of commentary about this buried on on this thread starting on page 2 about when the pressure goes back up to the set pressure with exhale relief for Resmed's EPR system and PR's C-Flex and A-Flex systems versus what happens in their corresponding bi-level machines if you're interested in the details.

There are also folks who have central, complex, or mixed apnea who wind up with bi-level machines for a different set of reasons that I won't go into because I'm not at all familiar with those conditions.

atruvirgo wrote:Can anyone give me a simple to the point description of what the various machines do?? I have CPAP but, having major aerophagia. I need a good argument for my doc as to which one would help.

I think cflame1 made a very good explaination of what each machine does. But before you try to push your doctor into getting you a different machine, make sure you have tried other ways to deal with the aerophagia. There are many on this forum if you do a search. Just some of them that I remember (I don't have aerophagia) are to make sure you are using exhalation relief on your machine (APR or C-Flex/A-Flex), sleep with your head slightly elevated, or if you sleep on your side, sleep with a slight curve in your back and your chin toward your chest. A simple search should come up with many, many posts dealing with this all-to-common problem.

Awesome explanations! I just made an appointment with a new pulmologist and I will review all of the info and try different techniques so that when I go to my appointment on Feb 23, I will be able to paint a clearer picture of my successes and failures. I just watched the video clip from resmed showing how an apnea affects the body. I have to say I wish I had watched it 3 years ago....it really made me scared of what sleep apnea does to the body. I had no idea that your heart rate drops up to 50% and then shoots up again. I turned my c-flex on last night and although I was awake by 1am I will try it again tonight.

Thanks Cpapers!

jbn3boys wrote:I think cflame1 made a very good explaination of what each machine does.

cflame1 put each type of machine into a nice nutshell with a few well chosen words -- including the words she used to start her post.

jbn3boys wrote:But before you try to push your doctor into getting you a different machine, make sure you have tried other ways to deal with the aerophagia. There are many on this forum if you do a search.
---
A simple search should come up with many, many posts dealing with this all-to-common problem.

Good advice from jbn3boys.

Besides using the forum's "Search" button at the top of this page, you might also want to try a Google search, atruvirgo. Sometimes that turns up more pertinent results than the forum's own "Search" feature.

Try a Google search like this:

aerophagia site:cpaptalk.com

or

aerophagia relief machine site:cpaptalk.com

In Google, run all that last part together with no spaces -- site:cpaptalk.com

cflame1 wrote:Without taking into account any kind of exhale relief or ramp/settling

CPAP - single constant pressure
APAP - single pressure moving between a lower number and a higher number
BiPAP/BiLevel (not Auto) - single inhale pressure and single exhale pressure (IPAP and EPAP)
Auto BiPAP/BiLevel (Respironics and Resmed do it slightly differently) - (Respironics) range of exhale pressures where the minimum is specified and range of inhale pressures where the maximum is specified. Max PS comes into play here determining what each of these should be.

Great post!

ResMed calls its bilevels "VPAP" instead of "BiPAP." ResMed auto bilevels operate with the IPAP and EPAP locked an exact distance apart from each other (a customizable constant PS) but then allows those two locked-together pressures to roam within a range that can be customized by specifying a minimum EPAP and a maximum IPAP.

Jeff (jnk) added another good nutshell to the pile.

"Nutty people...I'm on a message board with nutty people...and lovin' it."

Jeff's (jnk) great explanation about the difference in how the ResMed VPAP Auto (and "25") bilevel machine and the Respironics BiPAP Auto bilevel machine handle the "PS" (Pressure Support) setting is in this topic:
"ResMed VPAP Auto 25 Clinician's manual"
viewtopic.php?p=376749#p376749

Anyone want to tackle the "nutshell definition" of machines that would come AFTER bilevel, if you still need more?

jbn3boys wrote:Anyone want to tackle the "nutshell definition" of machines that would come AFTER bilevel, if you still need more?

Then it becomes time for the nutshell chart: http://sleepdevices.respironics.com/PDF ... pGuide.pdf