CPAP versus APAP

[Dawei]

JJJ--Following your scenario about the CPAP at 16cm eliminating the event while the APAP is working on it leads to the conclusion that a CPAP set at a high enough pressure will produce significantly better results than an APAP. Sorry, but I don't buy that. In addition, who wants to have a constant high pressure in their face (or up their nose) all the time when it's not needed.

[SuperSleeper]

Dawei, I'm having trouble deciphering which part of your posts are quoting someone else and which is your own post... and I've been trying to keep up with this thread.

Here's a how-to on how to quote properly:

http://www.apneaboard.com/forums/Thread-...85#pid3285

I think part of the problem is that you starting typing in the middle of a quote perhaps and then try to fix the quote tag and it gets goofed up maybe? - I'm not sure what's happening with your posts.

No big deal, it's just that it's difficult to know what is your own post and what is quoted text. You should be able to go back and edit those posts and fix it - I sure would appreciate if you did that.

[JJJ]

JJJ--Following your scenario about the CPAP at 16cm eliminating the event while the APAP is working on it leads to the conclusion that a CPAP set at a high enough pressure will produce significantly better results than an APAP. Sorry, but I don't buy that. In addition, who wants to have a constant high pressure in their face (or up their nose) all the time when it's not needed.

I agree with your second point. Having pressures higher than necessary decreases the comfort level, hence my original point about the value of APAP for improved compliance.

But why can't you buy the idea that a machine running at 16 cm. (in my original scenario) would eliminate an apnea event that a machine in auto mode at 10-16 might not react in time to avert?

[archangle]

And having said that, APAPs have one disadvantage over a CPAP, assuming the patient's pressure has been properly titrated. I.e., APAPs supposedly adjust to whatever the patient needs, but in real life practice they do not react fast enough. Suppose your APAP is set to, say, a 10-16 range. You are cruising along happily asleep at 10, and suddenly you have an apnea that requires 14 cm. to overcome. The machine will take 20-30 seconds to get all the way up from 10 to 14 because it keeps trying in 0.5 cm increments, waiting for the software to evaluate the results each time. If you had been running a straight CPAP at 16 that event would never have happened.

That's not a disadvantage to APAP, it's a choice of how you set the minimum pressure. If it bothers you, set the minimum pressure to 14. You still have some headroom to go up to 16 if you occasionally need it.

APAP gives you the choice of lower pressures most of the time vs. some temporary difficulty breathing.

Similarly, "monkey APAP" with the APAP set at 4-20 leaves you with a longer period of time to adjust upwards. One of the biggest requirements for proper APAP use is to set the minimum pressure high enough to give the optimal balance of treatment vs. delay.

I also find in my case, I feel better if I set my minimum pressure a little higher than the level that gives me essentially zero AHI. I presume I'm getting some degree of difficulty breathing even though I don't ever stop breathing completely.

[zonk]

And having said that, APAPs have one disadvantage over a CPAP, assuming the patient's pressure has been properly titrated. I.e., APAPs supposedly adjust to whatever the patient needs, but in real life practice they do not react fast enough.

not exactly the S9 autoset increase pressure and act pre-emptively to snore and flow limitation ... both of which precede obstructive apnea.

[JJJ]

And having said that, APAPs have one disadvantage over a CPAP, assuming the patient's pressure has been properly titrated. I.e., APAPs supposedly adjust to whatever the patient needs, but in real life practice they do not react fast enough.

not exactly the S9 autoset increase pressure and act pre-emptively to snore and flow limitation ... both of which precede obstructive apnea.

My understanding is that the PRS1 does this also, yet I can assure you that it is still not tast enough.

Having said that, it would be interesting to see a comparison of the algorithms used by the Resmed and Respironics auto machines. Not that we're likely to get that information easily. I'm sure they keep their code a closely guarded secret.

If one of them really reacts faster than the competition it would be a strong selling point.

[IDRIck]

Meta analysis is a very powerful research tool for aggregating data and analyzing trends across studies. Is it perfect? No. Is it highly valued and respected research within the scientific community? Yes. For those with an open mind, look at table 3 and you will see the results of 24 comparative studies. PAP therapy clearly reduces AHI and there is little difference in AHI reduction between APAPs and CPAPs.

Meta analysis is also a very powerful to to attempt to legitimize poorly done research by putting together a bunch of badly done studies. It's also a very powerful tool to manipulate results by introducing a selection bias.

Preparing a table of 24 badly done or irrelevant studies doesn't make the data any more correct.

Okay, you obviously believe that APAP are better. Please provide links/references to the well designed studies that clearly demonstrate significant biological improvements in OSA patients with a proper adjusted APAP over a properly adjusted CPAP. It should be easy since CPAP's were available first and are the gold standard. The new tech is always compared to the gold standard. I would sincerely like to read these studies. While I did not grow up in Missouri, I do like their "show me" motto.

Yes, yes, I do understand that my pressures would vary if I set my Autoset to APAP mode. I'm just not convinced that I would see any biological differences/improvements as my current therapy is effective and I am monitoring performance.

[IDRIck]

If you don't realize that an APAP machine is superior to CPAP, you simply haven't been paying attention. Anyone who argues otherwise has to be comparing "dumb APAP" to "smart CPAP."

You miss that obvious. I have successful results with a CPAP and question whether there any additional biologically significant benefits to converting to an APAP. I read lots of opinions but I'm not seeing good studies showing support. Show me, please, I'd like to read them.

Secondly, I feel I have excellent doctors and feel they have hit a home run with their recommendations. Based on the opinions expressed here, my doctors are way out touch and out of date. I disagree. It could be argued that they have taken a conservative approach and going with the proven, gold standard. I don't have a problem with a conservative approach.

[zonk]

Having said that, it would be interesting to see a comparison of the algorithms used by the Resmed and Respironics auto machines.

http://www.apneaboard.com/forums/Thread-...y-Pressure

here is algorithms comparison of different auto machines by sleep review Sept 2009 before the enhanced S9 autoset (see posts #1 &2)

[JJJ]

http://www.apneaboard.com/forums/Thread-...y-Pressure

here is algorithms comparison of different auto machines by sleep review Sept 2009 before the enhanced S9 autoset (see posts #1 &2)

Very interesting. Thanks for posting it.