APAP vs. CPAP

[DannyCPAP]

what is the difference between these machines and how it is decided which one to prescribe?

[zoocrewphoto]

cpap is continuous pressure at one setting. apap is automatic pressure which is set to a range.

Some people do better at one set pressure as their needs don't change much during the night, and/or a change in pressure wakes them up.

Others, like me, have different needs throughout the night. This could be because the apneas are worse during REM sleep and/or worse in different positions, such as sleeping on the back. I have a range of 11-17. For 95% of the night, my pressure is at or below 13. Some nights, it never goes above 14 or 15. Some nights, it goes up into the 16 range, usually topping out at 16.8, very close to the top of range setting. Since I don't need the high pressure all that much, I don't have to use it that much. But it is available when I need it.

[-tim]

Any APAP machine can work as a CPAP machine but not the other way around. They are the same hardware, they have been loaded with different software.

Your needs may change over the next 5 years and if the APAP machine is $40 more, it might be a good idea.

For new users, APAP seems to be easier to get used to and has a better range of settings that can be adjusted if you have problems. CPAP doesn't have nearly as many choices.

For some people, CPAP is needed but APAP can be used to get them used to it. Compliance with new users is higher with APAP than CPAP.

APAP has fewer side effects than CPAP. For example glaucoma and some blood pressure issues.

Also get a machine that records all the data. You never know when it will be helpful.

[Sheriff Buford]

Using Apap and cpap modes are a personal preference and one is not "better" than the other. Some folks feel better withe cpap mode than they do with the apap mode. Folks need to see what works for them.

Sheriff

[-tim]

Using Apap and cpap modes are a personal preference and one is not "better" than the other. Some folks feel better withe cpap mode than they do with the apap mode. Folks need to see what works for them.

Sheriff

That is mostly true.

For most cpap needs, apap is easlier to adjust to.

But there are reasons for pure CPAP mode (which tends to lead to VPAP in a few years).

[-SWS]

For most cpap needs, apap is easlier to adjust to.

There's a white paper kicking around somewhere on this message board. That particular study concluded there was no signifiant difference in patient compliance between CPAP use and APAP use. But I think we can question any methodology that runs APAP machines wide open, at 4cm-to-20cm. Intuitively, I think that above statement may be true. However, as epidemiology and empirical evidence go, I'm not aware of proof. I do know some people fare better on CPAP, others fare better on APAP, while others seem to do equally fine on either machine type. This message board has a long history of claiming APAP is superior to CPAP. So far researchers seem to have difficulty proving that...

I suspect anyone who recieves good control of obstructive SDB at low, fixed pressures around say 7cm or less will probably not see increased benefits from APAP. That said, I think it's nice to have an APAP machine, since it can run either CPAP mode or APAP mode. Patients can then decide if one of those two modes lends an advantage relative to their own sleep and physiology nuances.

But there are reasons for pure CPAP mode (which tends to lead to VPAP in a few years).

I haven't heard or read about that tendency. Do you mind my asking on what you based that statement about tendency? Here we can see a statement suggesting that CompSAS patients tend to find APAP mode more destabilizing to central breathing than CPAP mode:

CPAP therapy may be more or less effective in individual patients, but automatic CPAP machines should be avoided.

http://www.chestnet.org/accp/pccsu/comp ... a?page=0,3

Similarly, some patients find spontaneous BiLevel/VPAP mode to be more destabilizing to central breathing than CPAP mode:
http://journal.publications.chestnet.or ... id=1083869

I haven't stumbled across any conclusive evidence that pure CPAP mode tends to lead to a need for BiLevel/VPAP in a few years. Our message board documents plenty of patients in the U.S. who presumably need BiLevel from the very beginning----but must first prove failure on CPAP for the sake of satisfying insurance requirements. However, that particular trend seems based more on inane insurance bureaucracy than physiologic progression itself.

[DavidCarolina]

But I think we can question any methodology that runs APAP machines wide open, at 4cm-to-20cm. """""""""

......That is only a pre programmed range in resironics equipment. Certainly not a recommendation.

I use APAP and I've got it set to function between 13 and 19.

You can program yourself if your DME is being a pain about it.

I speak from experience, most of the people on this board know more about how to deal with their own apnea than
the doctors do.

[-SWS]

But I think we can question any methodology that runs APAP machines wide open, at 4cm-to-20cm. """""""""

......That is only a pre programmed range in resironics equipment. Certainly not a recommendation.

Well, 4cm-to-20cm certainly was a manufacturer recommendation. And most APAP research papers I have read employed 4cm-to-20cm ranges----likely based on the APAP manufacturers having recommended 4cm-to-20cm ranges. You'd be hard pressed to find APAP research using narrower ranges.

My point above is that we can and should question those white-paper APAP comparisons because of the wide-open ranges. Based on anecdotes, we know a wide-open APAP range doesn't always work well. I'd like to see research comparing CPAP to narrow and presumably more-suitable APAP ranges. However, I'll add those wide-open 4cm-to-20cm ranges must work well for SOME patients, since the manufacturers persist in recommending 4cm-to-20cm APAP ranges.

I speak from experience, most of the people on this board know more about how to deal with their own apnea than the doctors do.

I have absolutely no doubt that statement is true for SOME patients on this board. But the claim that more than 32,000 of this board's 64,000 membership possess superior treatment knowledge compared to their sleep doctors seems a bold and unsubstantiated claim...

How does one go about substantiating that claim into fact? That statement might well be true. However, if it's not true, then we impart a false sense of security about self-treatment to newcomers on this message board... My view is that a CPAP savvy patient and cooperative sleep doctor possess complementary knowledge, ideally yielding synergy in treatment decisions.

[jnk]

. . . a CPAP savvy patient and cooperative sleep doctor possess complementary knowledge, ideally yielding synergy in treatment decisions. . . .

I agree that docs sure come in handy for the diagnosis process and for prescribing treatment. Heck, some even come in handy for keeping DMEs in line and for troubleshooting problematic therapy.

But I also agree, in spirit, with the sentiment that . . .

. . . most of the people on this board know more about how to deal with their own apnea than the doctors do . . .

. . . in that, when it comes to the nuts and bolts of night-to-night success with masks, comfort adjustments, coping strategies, etc--it is good to learn here from fellow patients with experience actually using the equipment every night. I assume that may have been what David was getting at.

So is it OK if I agree with you both?

Ideally, I think, a doc would give parameters to patients but encourage patients to experiment responsibly within those parameters to find the lowest home-machine-reported AHI and greatest comfort. Oh but that such an ideal world existed!

[Madalot]

For me, I can't use one, set pressure as my needs vary too much during the night. My machine uses a range of 15-23.

My husband, on the other hand, can't tolerate the changing pressures. We used an APAP to figure out his average, then set the machine into CPAP mode.

What's interesting is that he COULD tolerate APAP mode on the S9 and slept fine with it varying the pressures. When we got the PR1 APAP, he couldn't sleep through the pressure changes on that machine. As this is a BIPAP, we tried BIPAP mode, but he still didn't like the changing pressures. He does better with one pressure (no ramp).

So, we have a BIPAP Auto, using it in CPAP mode. But we can always give him a few days in Auto mode if something changes in the future and his therapy doesn't appear to be as effective.

[Sheriff Buford]

For me, I can't use one, set pressure as my needs vary too much during the night. My machine uses a range of 15-23.

My husband, on the other hand, can't tolerate the changing pressures. We used an APAP to figure out his average, then set the machine into CPAP mode.

What's interesting is that he COULD tolerate APAP mode on the S9 and slept fine with it varying the pressures. When we got the PR1 APAP, he couldn't sleep through the pressure changes on that machine. As this is a BIPAP, we tried BIPAP mode, but he still didn't like the changing pressures. He does better with one pressure (no ramp).

So, we have a BIPAP Auto, using it in CPAP mode. But we can always give him a few days in Auto mode if something changes in the future and his therapy doesn't appear to be as effective.

The point I making is that each of use has their own comfort levels and needs. I don't need an apap to chase suspected apneas all night long. I want the cpap to keep my airway clear all night long. My sleep study resulted in a 70 AHI. With the cpap mode, I get an average of .3 AHI each morning. I know there are a lot of people that will kick themselves for not trying the cpap mode (if you use apap) or the apap mode (if you use cpap) once or twice a year to see how your numbers are and most importantly - how you feel. Just sayin'

Sheriff

[OldLincoln]

Some folks have a faulty lower esophageal sphincter which sits on top of you stomach and prevents contents from going up EG GERD, and air entering under CPAP. Valves don't fail in an all or nothing fashion but will begin leaking at a threshold pressure and leak faster at higher pressure.

I've tested my leakage and the threshold for me is 7.5ccm. So if I had a CPAP set at 7.0 I would not get bloating. But I need pressure into the 11ccm range and that bloats be up so I can't even stand until I vent it down to a tolerable level. So, I went to an APAP that is set for 6-16. Over 50% of the night it runs under 6 and a few percents at 7-10, and very few above than. That means I don't have any bloating over 50% of the night and little the rest. Remember air leaks a little at 7.5, just a little more at 8, etc. so the goal is to knock down the apneas while keeping pressure as low as it can. Works well for me.

As for why some do better with one brand over another is usually the code in the machine and one jumps the pressure up faster while other brands step it up slower. The faster rise disturbs some sleepers, and I prefer the slower also.

[avi123]

There are definite advantages to APAPs that many physicians and CPAPers don't know about. It could be because most sleep clinics don't do APAP titrations, and a physician rather not take the responsibility. Also, there several underlying medical conditions such as COPD, Heart problems, and Central Sleep Apnea syndrome, whereby APAPs should be avoided.

But Dr Colin Sullivan, the discoverer of the CPAP, gave APAPs lots of credits in his patent # 5,245,995 dated 1993. Check it here:

http://www.google.com/patents/US5245995 ... &q&f=false

Here is an excerpt from this patent referring to APAP:




Most of Resmed's patents for the Autosets are also based on this one patent.

In my case, I have wasted a full year by using a CPAP. In my sleep study from 2 years ago, whereby I had an AHI of 43 during the diagnostic night, I was prescribed a CPAP in the titration night with the wrong optimal pressure of 5-7 cm. It took me several months to titrate myself on that CPAP and realize that my best treatment was at 13 cm. If I had an APAP right then at the beginning I could realize it 6 months before. See here how lucky I am after switching to an S9 Autoset:

viewtopic/t79869/viewtopic.php?f=1&t=79 ... 26#p726726

[OldLincoln]

sws said there is a white paper posted that reports compliance is equal between APAP and CPAP. That must be recent as the studies I read a few years ago reported CPAP compliance at 50% and APAP compliance at 70%.

When my doc hesitated to script me an APAP I asked him why he would script anyone a solution that is only 50% successful when there is a solution proven to be 70% successful. Of course I had tried the CPAP for some time and couldn't take the bloating. But he did start thinking about it.

Since APAP can be set to CPAP and the price differential is so low I suspect someday APAP will be the norm. I wonder how much the supply chain would save if they only had the one machine. Perhaps they could erase the difference and the first brand to do so would capture market share by selling an APAP even if the DME set it to CPAP. The flexibility for options would be a big deal.

[avi123]

For most cpap needs, apap is easlier to adjust to.

There's a white paper kicking around somewhere on this message board. That particular study concluded there was no signifiant difference in patient compliance between CPAP use and APAP use. But I think we can question any methodology that runs APAP machines wide open, at 4cm-to-20cm. Intuitively, I think that above statement may be true. However, as epidemiology and empirical evidence go, I'm not aware of proof. I do know some people fare better on CPAP, others fare better on APAP, while others seem to do equally fine on either machine type. This message board has a long history of claiming APAP is superior to CPAP. So far researchers seem to have difficulty proving that...

I suspect anyone who recieves good control of obstructive SDB at low, fixed pressures around say 7cm or less will probably not see increased benefits from APAP. That said, I think it's nice to have an APAP machine, since it can run either CPAP mode or APAP mode. Patients can then decide if one of those two modes lends an advantage relative to their own sleep and physiology nuances.

But there are reasons for pure CPAP mode (which tends to lead to VPAP in a few years).

I haven't heard or read about that tendency. Do you mind my asking on what you based that statement about tendency? Here we can see a statement suggesting that CompSAS patients tend to find APAP mode more destabilizing to central breathing than CPAP mode:

CPAP therapy may be more or less effective in individual patients, but automatic CPAP machines should be avoided.

http://www.chestnet.org/accp/pccsu/comp ... a?page=0,3

Similarly, some patients find spontaneous BiLevel/VPAP mode to be more destabilizing to central breathing than CPAP mode:
http://journal.publications.chestnet.or ... id=1083869

I haven't stumbled across any conclusive evidence that pure CPAP mode tends to lead to a need for BiLevel/VPAP in a few years. Our message board documents plenty of patients in the U.S. who presumably need BiLevel from the very beginning----but must first prove failure on CPAP for the sake of satisfying insurance requirements. However, that particular trend seems based more on inane insurance bureaucracy than physiologic progression itself.

Comment,

I don't think that -SWS was fair by posting the above links to ComplexSAS (which may require ASV machine), and to the BiLevel, in this conversation, b/c the topic is APAP vs. CPAP.