APAP with A-flex vs BiPAP

What is the effective difference between an M Series APAP with A-flex and the Auto BiPAP with BiFlex? Other than $600?

Although I am fortunate that my insurance is paying for the BiPAP, I can't help but wonder what the difference is. My prescribed pressures are 20 IPAP and 15 EPAP. Couldn't an APAP machine provide therapy at that level?

Thanks,
Susan

I believe that those pressures are at the top of what the Auto... non Bipap can handle.

Susan,

The Auto with A-Flex provides a more comfortable style of pressure relief than you get with C-Flex. In a way it does resemble standard BiPap in that with A-Flex, the machine pressure can vary up to 2 CMS from breath-in pressure to breathe-out pressure. A-Flex tries to track your natural breathing cycle & as you breathe out, it relaxes the pressure.

C-Flex & Bi-Flex merely inject a very small period of pressure drop when the machine detects you are breathing out. It is a way of making it seem easier to breath out against the normal pressure the machine is at. It really offers greatest benefits to people on higher pressures (say > 14 CMS) who find that switch to breathing out hard, but C-Flex & Bi_Flex have also proved very popular with people on lower pressures.

Where A-Flex goes beyond C-Flex & Bi-Flex, is that it not only adds the pressure dip when you switch to breathing out but tracks your breathing and will hold the pressure down longer (to a max of 2 CMS below normal), then bring pressure back up to normal pressure as the machine detects your breath-out cycle ending. It is an extension of the Auto-Trak algorithm and for most people is going to be a very comfortable way to get used to xPAP therapy.

DSM

Thanks, cflame1 and dsm.

If I understand you both correctly, the spread between the inhale and exhale pressure is greater on the BiPAP machine than it is on the AutoPAP with C-flex. Since my Rx has a 5cm difference, the Auto CPAP would not provide the appropriate exhale pressure since it can only go 2cm below the max.

Thanks again,

Susan

Perchance--you are correct. With the BiPAP you clearly set IPAP and EPAP. With the Auto with A-Flex, you don't. The BiPAP is a clear bi-level device for use in higher pressures. I hope you get a good night's sleep.

Perchance, the machine I'd be trying to get if I were you is the machine that can work both ways at the same time...as an autopap to vary the pressure as needed (in case you don't need that IPAP of 20 all the time, all night, every night or in every sleep position and sleep stage) AND at the same time operates as a bipap, giving pressure relief throughout the entire exhalation.

That "best of both worlds" (imho) machine is the Respironics BiPAP Auto with Bi-flex.

As icing on the cake, although I hope you don't need more pressure...that machine can go considerably higher than the 20 cmH20 which is the maximum pressure that cpaps and autopaps can use.

That machine is, first and foremost, a "bipap" machine and requires a bipap (bi-level prescription.) It is not an autopap, even though it does have the auto-titrating feature that can be turned on so that the IPAP / EPAP pressures can vary independently of each other, as needed throughout the night.

It can also be used as just a bipap if that is better for a person.

I don't even need that kind of machine, but it's the one I choose to use. It's so darn comfortable.

Perchance,

Added to all the other excellent suggestions, you could also consider the Resmed Malibu VPAP Auto.

How it differs from the BiPap Auto is that it will hold the ipap to epap gap constant to what ever ther RT sets it to (e.g. 5 CMS) whereas the Bipap Auto allows the gap to change during the night (you can't stop this other than to exit Auto mode) the BiPap Auto can change from a minimum 2 CMS gap to a maxPS as set by the RT (absolute max can only ever be 8 CMS).

Unfortunately there are no useful studies that tell us if one approach is better than the other however the other new Resmed VPAPs (SV models) have received a lot of positive feedback and in regards to the Bipap Auto, there are a lot of users here who are very happy with them.

I personally like my PB330 set to BiLevel mode with 13 CMS breathe in and 10 CMS breathe out pressures. I really like its consistency.

I can't really see the benefit of a BiLevel *and an* Auto at the same time - it to me makes the whole experience inconsistent.

The purpose of an Auto is the try to overcome the frustration some people have with trying to breathe out against a constant CPAP pressure. The higher the pressure the harder to breathe out & also the higher the pressure (say 14+) the more mask problems one is likely to have. C-Flex and Bi-Flex offer some assistance in that area.

The purpose of a BiLevel started out to be to help people with lung problems who needed every bit of help to breath out without the usual effort to do so when on a CPAP, and particularly when on higher pressures (say > 14). Early BiLevels were very expensive. Today they are much more affordable & many people swear by them. One example often cited why BiLevel is so good is a significant reduction for people, of the effects of aerophagia.

For a while, people who wanted to monitor their own therapy, only had the Autos to turn to as prior to about 2005/6, Most BiLevels did not provide the same detailed nightly data that Autos were able to do. But in 2005/6 that changed when BiLevels such as the Bipap Pro 2, Bipap Auto, VPAP III etc: offered detailed nightly data that included detailed AHI data as well. Early BiLevels mostly provided minute ventilation data, pressure data & only nightly summary AHI data.

So for me, a BiLevel offers the best of therapy and provides a consistent experience whereas Autos BiLevels try to do two different jobs at the same time & keep shifting the pressures which to me adds more problems than it solves this is compounded on the Bipap Auto which doesn't even allow you to lock the ipap to epap gap unless you exit Auto mode.

Good luck on your choice.

DSM

based upon your pressure(s), I'd get the Bipap Auto w/Biflex.

Biflex and A-Flex are nearly identical (if not the same), they both round off inhale and offer relief at the beginning of exhale.

The difference is the Bipap can go up to higher pressure (25cm) so you are not maxed out as soon you get your machine and the Bipap can run in different modes including Bilevel.

While AFlex is nice and easy to breathe against, but you need the Bipap Auto based upon your pressure requirements. The Bipap auto will offer you the most relief.

[quote="Perchancetodream"]Thanks, cflame1 and dsm.

If I understand you both correctly, the spread between the inhale and exhale pressure is greater on the BiPAP machine than it is on the AutoPAP with C-flex. Since my Rx has a 5cm difference, the Auto CPAP would not provide the appropriate exhale pressure since it can only go 2cm below the max.

Thanks again,

Susan

dsm wrote:I can't really see the benefit of a BiLevel *and an* Auto at the same time - it to me makes the whole experience inconsistent.

I have a different perspective on the benefit of a machine that can auto-titrate while operating as a bi-level machine at the same time. The benefit I see (and have felt every night for over a year using the BiPAP Auto with Bi-flex) is the wonderful pressure relief on exhale using "bipap" along with the assurance that with auto-titration turned on, I'm not having more pressure than necessary pushed at me throughout the night. Unnecessary pressure that can cause masks to be more likely to leak, or cause aerophagia.

Many people have changing pressure needs depending on whether they are on their back (needing more pressure) or on their side (less) -- are in REM (more) or in other stages of sleep (less.)

Makes perfect sense to me that a BiPAP Auto machine which is capable of varying the pressure as needed while at the same time offering pressure relief throughout the entire exhalation can make breathing while sleeping exceptionally comfortable. Especially for people who have been prescribed extremely high pressures like the 20 IPAP Perchance is facing. The smoother and more comfortable breathing can be, the more likely we are to be able to actually sleep.

Sleep studies are usually designed to find the pressures needed for worst case scenario -- on one's back and in REM. It's very unlikely a person will have both those situations going on the entire night. A person might not actually need that worst case scenario pressure (or pressures if prescribed bi-level IPAP/EPAP) but a few times, if any, during any particular night.

In other words, Perchance might get excellent treatment with less than IPAP 20 / EPAP 15 much of the night. Thus, the beauty of auto-titration finding the pressure that's actually needed on a changing basis. But no matter what auto-titrating pressure a machine is using at any given time, it can be MUCH more comfortable for many people to also have a bi-level machine's complete exhalation relief from "whatever" pressure is being used at the moment.

Sure, a person could go just autopap. But even autopap with A-flex is not going to give relief thoughout the ENTIRE exhalation the way a bi-level machine does.

When a person is prescribed an IPAP of 20 / EPAP 15, I think that's definitely the time to think seriously about trying to get both kinds of pressure relief while still getting effective treatment. Autotitration to vary the pressure as needed AND the complete exhalation relief of a bi-level can provide that in many cases. If varying the pressure doesn't suit the person, autotitration can always be turned off and they still have a bi-level machine for exhalation relief.

dsm wrote:The purpose of an Auto is the try to overcome the frustration some people have with trying to breathe out against a constant CPAP pressure.

I don't think that's the "purpose" at all of an autopap. The purpose of an autopap, or at least why they were developed in the first place, as I understand it, is to find a pressure that takes care of preventing apneas/hypopneas at least 90% of the time. The purpose, as far as I know, for invention of the autopap was to use the autopap just long enough to discover an effective single pressure and then put the person on a straight cpap machine at that pressure,

Using an autopap per se is not necessarily going to give relief from trying to breathe out against a constant pressure. Because there is going to be one straight pressure being inhaled and exhaled against at any given time when using an autopap. That one pressure may vary throughout the night, but it is going to be one single pressure breathing in and breathing out during any one respiratory cycle (inhale/exhale.)

Overcoming "the frustration some people have with trying to breathe out against a constant CPAP pressure" can be addressed most of the time through either of these two firsts from Respironics:

1. C-flex -- the first exhalation relief of any type in straight cpap machines
2. BiPAP -- the first bi-level machine

And more recently, another first -- A-flex in the M series Autopap to give what several on this board have described as feeling very smooth and natural, very much like breathing with a bi-level machine.

I agree that an autopap can add the comfort of not dealing with more pressure than necessary. I just don't think that was the purpose for the invention of auto-titrating cpap machines.

The BiPAP Auto offers the best of both worlds, imho. I can certainly see why both bi-level and auto-titration working together can give a much more comfortable experience for many. I see a lot of benefit in being able to breathe more naturally at less pressures than with machines that can do only one or the other.

But, of course each person's experience with different machines can vary. It's good there are so many different types of machines with different features out there. It's also good when features can be turned off if they don't suit a person.

RG,

The great thing about cpaptalk is that we can all have different perspectives and discuss them freely.

I remain convinced the primary purpose of the Auto was to develop a machine that would help reduce the burdens of therapy that people were experiencing using straight cpap therapy.

You commented "The purpose of an autopap, or at least why they were developed in the first place, as I understand it, is to find a pressure that takes care of preventing apneas/hypopneas at least 90% of the time".

Let us look at this statement from United States Patent 5645053 - The Patent Issued on July 8, 1997 (Healthdyne).

"OSA therapy is implemented by a device which automatically re-evaluates an applied pressure and continually searches for a minimum pressure required to adequately distend a patient's pharyngeal airway . For example, this optimal level varies with body position and stage of sleep throughout the night. In addition, this level varies depending upon the patient's body weight and whether or not alcohol or sleeping medicine has been ingested. "

I have highlighted the critical point "minimum pressure required to adequately distend a patient's pharyngeal airway". This became important because of the compliance failure with straight CPAP. I am sure we both know that a straight CPAP back in the late 1990s tried to solve the OSA problem by delivering a constant pressure calculated by setting the minimum pressure needed to keep the users SpO2 reading in a particular range as well as reducing snoring and obstructions. The AHI number is more or less the measure that indicates success. But, back in the 1990s CPAP machines did not all have pressure transducers that allowed them (like modern CPAPs) to ease the applied pressure as the patient tried to breathe out. Nor did users have software to monitor their therapy. Using that is another side effect that has become a very popular aspect of taking control of one's own therapy and Autos were the first machines on which useful data was available.

Restated, in the early CPAPs a user's breathing out was in opposition to the CPAP which was trying to maintain the same constant pressure in. The user had to 1st oppose the force of air in, then overcome it, then exceed it in order to expel the air in their lungs. This combined pressure caused the mask pressure to go substantially higher than the pressure needed to keep their pharyngeal airway open. In turn, the elevated pressure caused uncomfortable side effects in most users who were on medium to higher pressures.

Problems with straight cpap led to the compliance failure rate which was always very high and this was really due to 2 aspects of cpap therapy, the problems associated with breathing out against a high fixed pressure and 2, the mask problems that occurred in the early cpap machines due to the transient high pressures when a user switched from breathing in to breathing out.

I do not believe that Autos were invented wholly to perform titration which is more or less what your words imply. The patent application shown doesn't take the position you have. Doing titration is a side benefit of Auto machines and I would agree that is why most clinics now use Autos to do titrations.

The main purpose was only ever to improve therapy and compliance. So I believe Autos were invented along with just about all other types of xPAP machines, to improve the therapy experience for users and to improve CPAP compliance. Titration benefits were a plus.

It may be that we are in agreement but coming at the matter from different angles.

**************************

One aspect your comments fails to address is any complications arising from constantly changing the pressure from the machine to a user during the night. I believe the jury is out on if this is a downside of an Auto machine. There are certainly many many experienced people who have commented here on cpaptalk how after some months they gave up running their Autos in Auto mode. I fit into that category.

Do you know of any studies that might address the issue of the effects of using varying pressure (Autos) ?.

**************************

You said "I'm not having more pressure than necessary pushed at me throughout the night."

BiLevels solve this issue very well and are now affordable. Varying the pressure on top of providing relief through dual pressure is pure overkill for the average person and more of a sales gimmick that a practical benefit.

I do believe that the few of us on CMS pressure around 20 CMS may get benefit from ...

1) Varying the pressure using the Auto function PLUS
2) Varying the pressure by also allowing switching the lower epap pressure AND
3) Varying the pressure yet again with BiFlex

But the average person here seems to be well under 20 CMS and there is still the doubt that varying the pressure causes its own complications. That issue IMHO really needs research.

***********

This part


Overcoming "the frustration some people have with trying to breathe out against a constant CPAP pressure" can be addressed most of the time through either of these two firsts from Respironics:

1. C-flex -- the first exhalation relief of any type in straight cpap machines
2. BiPAP -- the first bi-level machine


comes across to me as marketing spiel

Cheers

DSM

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CPAPopedia Keywords Contained In This Post (Click For Definition): respironics, bipap, C-FLEX, Titration, CPAP, AHI, auto, Bi-Level Machine

[quote="Perchancetodream"]Thanks, cflame1 and dsm.

If I understand you both correctly, the spread between the inhale and exhale pressure is greater on the BiPAP machine than it is on the AutoPAP with C-flex. Since my Rx has a 5cm difference, the Auto CPAP would not provide the appropriate exhale pressure since it can only go 2cm below the max.

Thanks again,

Susan

rested gal wrote:Perchance, the machine I'd be trying to get if I were you is the machine that can work both ways at the same time...as an autopap to vary the pressure as needed (in case you don't need that IPAP of 20 all the time, all night, every night or in every sleep position and sleep stage) AND at the same time operates as a bipap, giving pressure relief throughout the entire exhalation.

That "best of both worlds" (imho) machine is the Respironics BiPAP Auto with Bi-flex.

As icing on the cake, although I hope you don't need more pressure...that machine can go considerably higher than the 20 cmH20 which is the maximum pressure that cpaps and autopaps can use.

That machine is, first and foremost, a "bipap" machine and requires a bipap (bi-level prescription.) It is not an autopap, even though it does have the auto-titrating feature that can be turned on so that the IPAP / EPAP pressures can vary independently of each other, as needed throughout the night.

It can also be used as just a bipap if that is better for a person.

I don't even need that kind of machine, but it's the one I choose to use. It's so darn comfortable.

Rested Gal,
HI I dont understand how it isn't an auto pap?? I was going to post this question today anyway, asking if bi flex was the same as the aflex and cflex used on the auto cpap.. i am confused on the auto part though?

All, this is a very good discussion.

I just got off the phone with my DME and we agreed they would submit the paperwork to my insurance company this morning for an A-Flex. Doc wrote a prescription for apap stating "cpap not tolerated due to aerophagia". DME believes the insurance company will approve the purchase even though they just bought me a cpap machine 20 months ago.

I have been at 10 cm straight cpap and am having bad aerophagia when I roll to either side. So I want to get a new machine to try to relieve the aerophagia (and it will be nice to have data capability).

Do you think the A-Flex is a good decision or should I have chosen a different machine?

[quote="rooster"]All, this is a very good discussion.

I just got off the phone with my DME and we agreed they would submit the paperwork to my insurance company this morning for an A-Flex. Doc wrote a prescription for apap stating "cpap not tolerated due to aerophagia". DME believes the insurance company will approve the purchase even though they just bought me a cpap machine 20 months ago.

I have been at 10 cm straight cpap and am having bad aerophagia when I roll to either side. So I want to get a new machine to try to relieve the aerophagia (and it will be nice to have data capability).

Do you think the A-Flex is a good decision or should I have chosen a different machine?