Medical Rationale for CPAP over APAP?

[Newsgrouper]

I see that the APAP is the overwhelming choice of the experienced folks on this board. With this in mind I would like to know the medical arguments in support of CPAP over APAP. Why do doctors choose CPAP for their patients when APAP is available? I'm not seeking speculation but rather the reason doctors have given their patients for choosing CPAP. I'm especially interested in the rationale doctors have given their patients, who have specifically requested APAP, when denying their request.

[-SWS]

Okay, so the purpose of this thread in not to argue in favor of AutoPAP, but rather to try and understand the doctors' arguments against AutoPAP. In the spirit of understanding the pro-CPAP mindset, here are some possible arguments or considerations that doctors may take (admittedly some of these rationale are not purely medical in nature):

The venerable CPAP is the oldest xPAP platform, with an established track record of being the "gold standard of treatment". Many doctors perceive CPAP to be "tried and true" compared to AutoPAP.

A CPAP machine has no sleep event detection and triggering shortcomings, since it delivers fixed pressure---a much simpler technical task than either BiLevel or AutoPAP.

A CPAP machine is promoted above all else by the vast majority of players in the medical establishment---from the sleep lab near the front end of the process all the way to the DME at the back end of the process.

An AutoPAP is perceived by many doctors to either over treat or under treat all too frequently.

The original AutoPAPs that were less effective still seem to tarnish the reputation of even modern AutoPAPs in the minds of many doctors.

A CPAP is much easier for the doctors and RTs to understand and therefore administer than technically complex AutoPAP or BiLevel

An AutoPAP just may be perceived by some in the sleep industry as potentially denying follow up revenue by the way of PSG retitrations

[Guest]

ok another answer is Money . insurance company reimburse for 2 things
Bipap and CPAP . APAP is more money and is not considered a BIPAP which has the higher reimbursement. Combine that with all the other reason posted above. APAP will never catch on for DME use unless the price = the cpap or the insurance companies reimburse more.

[wading thru the muck!]

There is NO reason to buy a cpap instead of a apap. An apap can be set to be a cpap, but cpap can only be a cpap. The extra $200 to $300 an apap costs would be saved 5-10 fold if it saves you needing to get re-titrated.

[unclebob]

Hi Newsgrouper,

My sleep doc said the algorithms in the APAP were not proven and that he had many studies to prove this. He told me APAP's were being flogged only by the manufacturers to promote profit. He advised me that he would not be responsible for my treatment because with an APAP he would never know what pressure I was at in the event of any emergency.

The doc made it clear that my titration, which encompassed many factors, was X% and this should not be deviated from.

This is the same doc who:

- would not give me my prescription.
- delayed my xPAP acquisition by not fully explaining the process.
- assumed I would rent a standard CPAP unit for some period of time.
- spent less than 5 minutes with me on my first appointment and did not
acknowledge my persistent nasal congestion.
- would not give me the results of my titration but rather sent me a copy of
the two letters sent to my family doc who had referred me which only
summarized the results of my two studies. This was done only after
repeated requests.
- spent less than ten minutes with me at my second appointment which was
approximately six months after my first meeting with him.
- would not even look at my print outs of the smart card results for over two
months of usage with almost 100% compliance.
- who berated me for outright purchasing a Remstar Auto CFLEX and stating
the only reason I received gov't funding is the unit had a CPAP
component.
- who the second I left his office called my supplier who in turn tried to
pressure me into returning the APAP unit to adjust the pressure to the
doc's original prescription - which I had altered to reflect his prescription
as the low setting. He did not provide a range.

I have had significant interaction with the medical profession in the past few years with a number of life threatening incidents and major operations. In every case my care has been exemplary and I am truly thankful for the wonderful help and attention I have received from each and every doctor (many) and nurse (more than many). Even the weeks and weeks of Jello was good. Ambulance drivers(5) and attendants were great - really enjoyed the sirens and lights whizzing by the multi lane stalled freeway traffic during rush hour heading into downtown Toronto when the Exhibition was on as well as a Blue Jay game on a Friday night. Cool, hey I lived!

The worst encounter I ever had was with my sleep doc.

My take on the situation is that some old guy has found a niche where he can still profess to be a practicing physician in an otherwise ignored or at least undiscovered area of medicine and continue to call himself a doctor. The bucks are still plentiful. Few have been trained or at least explored Apnea as a traditional branch of medicine, those who are in it already can suck the system dry in a high handed and secretive manner

These people feel threatened and overwhelmed with the attention and progress being made in this area and are simply trying to protect their turf. They are getting in the way of progress and ignore patients who seem to be more "with it" who have only read Reader's Digest and noted a few comments by interested "non doctor" types on the Internet whose only motives are to understand their own health issues.

So, back to the question. Why do posters on this board prefer APAP to CPAP and what is the medical rational given for only CPAP prescribed by certain members of the medical profession?

Because the posters know better ( Thank you 1000 club members for your tried and true experience, and to those other techie/research you know who types who give us a bucket full of facts and links and researched reports) and because not only are the medical professionals following the bucks - some are just too damn lazy to investigate new initiatives or set in their pompous ways to acknowledge the (pardon the pun) winds of change.

Sorry for the rant but I just cannot accept in my own mind that all I have learned on this subject, even with first hand use, can be summarily dismissed by a so called expert in this field.

Thanks to all for sharing.

Bob F

[chrisp]

So to sum it up. Follow the money !

[ozij]

There is NO reason to buy a cpap instead of a apap. An apap can be set to be a cpap, but cpap can only be a cpap. The extra $200 to $300 an apap costs would be saved 5-10 fold if it saves you needing to get re-titrated.

Wader's message reminds us that there are two very different issuses here:
1. How you use the machine - straight PAP or AUTO
2. Which machine you buy: one that lets monitor your results on a daily (nightly) basis, or one that doesn't. As far as I know, straight CPAPs don't have monitoring software on them or with them. (They are the computer worlds equivalent of a "dumb terminal", as opposed to a PC or Mac)

The doctor might have a medical rationale for how you set up the machine. But the patient may have his/her own rationale for monitoring the treatment. Plus, if you feel the need, you can use it for retitration.

The bottom line therefore: If your doctor wants you on straight PAP for medical reasons, and you trust her/him, buy an AUTO, you will get it set up according to the doctor's prescription, don't change it - and you will be able to follow your therapy while you're reading and learning more about the subject.

It's up to you to figure out which of the doctor's reasons are medical, and which have other, vested insterests in them.
O.
[/b]

[VancouverBreeze]

Just to clarify...my REMstar PRO CPAP does have a smart card, and if I ever got so curious I could monitor...something....what....I don't know!!

Darren

[Davidmcc]

Having recently revisited my sleep specialist, without telling him I have the auto I ran through what would for him be a "normal" follow up visit. I consider this was, to a large degree, a waste of his time and my money. This appointment largely comprised my telling him how I was now feeling with him making recommendations acting on the not unreasonable assumption that I am using a normal cpap, set at the prescribed level some weeks/months ago, that could at best tell him how many hours the machine operated.
In the absence of my subjectively deciding my condition has or has not improved he would have no basis for making any further recommendation concerning my ongoing treatment without requiring a further overnight sleep study.
However, I am due to see him again in six months time When I will take in some current reports and we will have a much more interesting discussion of how the the treatment is progressing.
I suspect that the CPAP Pro 2 with Cflex, or a similar machine, which does provide a more realistic recording reporting facility will be the preferred recommendation in the future as patients having this machine will able to provide a smartcard or similar device to their doctor that provides him/her with some significant information on the effectiveness of the treatment and/or the need for change, without necessarily requiring a sleep study.

[ozij]

Thank you, VancouverBreeze (welcome back from your tosilectomy ) and
Davidmcc :

Correction of what I wrote:

There are non-auto machines with data collection capacity. Specifically:

With the REMstar PRO CPAP you can only monitor your compliance (that's if you don't know...)

With the CPAP Pro 2 with Cflex you can also monitor the objective results of the therapy - the machine gives you Cflex exhalation relief, but does not vary the inahalation pressure.

O.

[Vicki]

My sleep doc proved to me the advantage of a CPAP during a sleep study. My study clearly showed that my APAP spiked erroneously high pressures which caused multiple arousals and greatly disrupted sleep as opposed to when I was on CPAP. So the algorithms still need work.

This reason, plus the fact that you have to have, at the very least, beginnings of an apneic event to trigger an APAP pressure change, are the reasons most sleep labs and docs. are not recommending them at this time. When APAPs first became available as a patient alternative to CPAP, they were embraced as a great idea for many reasons, but the results just haven't lived up to expectations.

Vicki

[wading thru the muck!]

Vicki,

Most Docs and Sleep labs don't recommend auto machines because most DMEs don't want the extra expense of providing them. Every auto on the market can be switched to a fixed pressure machine, so you are not losing anything by getting an auto. One machine, the Puritan Bennett 420E has several adjustable settings that may prevent the pressure spikes you encountered. On the REMstar auto I have found that if you keep the bottom end of the range high enough to prevent snores, that it seldom runs up the pressure. Docs are just not spending enough time working with the auto units to learn how thy work. Straight CPAP is cheap and easy... that's why they push it without regard to the comfort of many of their patients.

[Liam1965]

My sleep doc proved to me the advantage of a CPAP during a sleep study. My study clearly showed that my APAP spiked erroneously high pressures which caused multiple arousals and greatly disrupted sleep as opposed to when I was on CPAP. So the algorithms still need work.

Vicki,

Unfortunately, what your doctor provided you with was not enough information. WHICH Auto did he use? That's a vital piece of information, because each of the three main Auto machines (although "Auto" is actually a trademark of one of them) have different algorithms. As a result, claiming that "the" algorithm of Auto machines needs work isn't fair.

Not only that, but the machines have (reportedly) undergone huge leaps forward in the last few years, such that if the doctor used a 2-3 year old APAP machine, that would be like an ecologist "proving" that all cars were gas guzzling monstrosities by taking you for a test drive in a 70s era vehicle.

But the main thing I think doctors miss when preferring straight pressure over Auto (mine even rejected CFLEX, for the same basic rationale yours gave for Auto) is that comfort is essential for compliance. I would (unhappily) remain compliant on something which was uncomfortable if it WORKED, but by it's nature, if an apnea treatment is not comfortable, it is going to disturb your sleep as much as the apnea does. This was my problem. I might have not stopped breathing with my CPAP machine on, but the whole affair was so uncomfortable, I almost never got to sleep at all. So I traded in poor sleep for almost NO sleep.

So in my case, if CFLEX, or auto-titrated pressure, or a Keebler elf chanting Native American rain dances around my room could make my treatment more comfortable, it was worth the drop in efficacy of the treatment. Ultimately, for me, *NO* treatment (a drop in efficacy of 100%) has worked better than ANY of the above. So my argument to my doctor (which he dismissed, by the way) was "Is use of an Auto machine really a worse choice than not treating my apnea?"

When comfort is factored in (particularly for patients with higher pressures), I think the Auto is the clear winner. Sure, it might miss an apnea or two that straight pressure might have caught and dealt with. But if your mask is on the floor next to your bed, because it was too uncomfortable, or if you're lying awake when you could be asleep (for the same reason), then the straight pressure did NOT ultimately do you any favors.

Liam, arguing against being straight. Who knew?

[Liam1965]

Oh, I had two more thoughts.

First, I don't get the argument that Autos wait until an apnea event is underway before responding, because for a lot of apnea sufferers, the problem isn't the arousals (although granted it was for me, and sounds like it was for Vicki), for most it's the drop in O2 saturation. Now, if you're going to have a 30 second apnea, sure a straight pressure MIGHT eliminate it entirely, but how much O2 drop does one actually get from waiting for 1-2 seconds before starting to breathe again? Still a lot better than waiting 30 seconds and waking up before doing so. And it would seem to me that the body would get used to a straight pressure (in the same fashion that some drugs lose their efficacy if you take them too often), while Auto would be more like only taking a low dose regularly, so that the higher doses needed therapeutically would still remain effective.

Second, there's central apneas. Straight pressure not only does nothing to solve them, it can actually INDUCE them. I found myself suddenly gasping for air when I was on the straight pressure (before some kind soul told me how to give my doc the metaphorical finger by turning on my own CFLEX), and I'd realize that I'd suddenly forgotten to breathe. After adding CFLEX to the mix, that happened much less frequently, but it still happened.

At least one of the major Auto algorithms has ways of determining if your current apnea event is a central or an obstruction, and will then DROP the pressure if it determines it's a central, which is the correct treatment for a central. So for folks like me, subject to pressure-induced centrals (even at the relatively low 9 pressure I was at), Auto would clearly be better in this regard.

Liam, who never got to try it to find out.

[Guest]

There are problems still with the Auto sets algorithms. They are getting better but an Auto set is not going to replace a good CPAP titration. The best thing to do is to keep the parameters very close. Start out with the minimum pressures that you needed for most of your sleep study. That’s the pressure you needed to keep your airway open in stage 2 not what you like to fall asleep on .That’s why an auto still has a Ramp or settling function for set that at your 4-5 cmH20 for 20 min . So if they had you at 8 for most of the night but had to jump to 12 when you went on your back or in a REM then 8 cmH2o is the low number you want. Make the MAX pressure 2 cmH2o over the pressure they said you needed on a regular CPAP. So if your prescribed pressure is 12 cmh20 set the high at 14 not 20 cmh2o .This will make the pressure changes very close and not go wacky and wake you up. It will also allow for what the Auto pap was designed for give you the pressure you need from night to night. Maybe you’re a little extra tired one night or had one to many drinks so you need some extra boost. Letting an auto go from 4 cmH20 up to 20 cmH20 is to far a range. Keep them close. So in a scenario like this I would set the pressure from 8cmH20 to 14 cmh2o. I see allot of settings from 4 to 20 or 4 -16 when they never get over 8. I would only recommend an Auto to a pregnant women or some one who is changing weight rapidly up or down. If you have problems with getting use to the pressure then go to the FLEX. I went to the Bi-Flex and I found that to be SOOOOOoo easy to breathe on. I tried the Auto but not the Auto flex yet. If you go up in pressure needs then raise the parameters up together. If you leave it to spread this is when your giving it to much freedom and it allows for more mistakes to be made.