(04-24-2016, 08:26 PM)palerider Wrote: robysue just posted a link to a 2015 study that, once again, shows that resmed apaps treat breathing problems faster than other machines, and thus don't leave you in apnea as long.
though I'm sure other will dispute that simplistic summary
Palerider is oversimplying the results of that study and also ignoring the fact that Resmed payed for it. Among other things, the particular bench test that Palerider talking about had the tested APAPs running in a wide open pressure range (4-20), the apnea sequence fed to the machines needed 12cm to "eliminate", and the machines were run for only 30 minutes. These conditions favor machines with aggressive responses, but they do not necessarily reflect what happens to a real patient who has the APAP range set in an appropriate fashion.
There are advantages and disadvantages to both machine's auto algorithms. Yes, the resmeds respond faster, but as a result they can over respond
---i.e. they can increase the pressure so rapidly that it causes arousals or they can increase the pressure beyond what is technically needed. That also turn can cause arousals and/or aerophagia to become an issue. It's worth noting that in the bench study, "regular" mode for the A10 AutoSet increased the pressure by almost 14cm (from 4 to 17.8) in about 5 minutes; the "for her" mode of the A10 increased the pressure by almost 11.5 cm (from 4 to 15.4) in about 5 minutes. And since 12cm of pressure should have been enough to stabilize the breathing and "eliminate" the apneas, it can be argued that in both modes, the A10 over titrated the "patient" and in the regular mode, the A10 significantly over titrated the "patient". And while some people might sleep soundly through such a steep pressure increase, a lot of other people would arouse or come to full wake as a result of that kind of a pressure increase.
I personally just could NOT adapt to the S9 AutoSet that I started out with. I can't prove
the problem was the way the S9 chose to aggressively respond to events, but I do believe that was at least part of the problem. But please note, that I was moved from the S9 AutoSet to a bilevel machine. At the time I had a choice of either getting an S8 VPAP Auto, getting a System One BiPAP Auto, or waiting an unspecified amount of time for the S9 VPAP Auto to be released. After much thought and research (done on the other forum), I decided to go with the System One BiPAP. It proved to be an advantage in that my stomach appreciates the System One BiPAP's ability to leave EPAP alone when the problem is flow limitations or hypopneas. The PR search algorithm does not bother my stomach the way the wild swings of pressure on the S9 AutoSet did.
In other words, it's important to keep in mind that it is necessary to be able to sleep comfortably with whatever PAP machine you are using. And if you can't sleep with the machine, it doesn't really matter how well the machine performed in an artificial bench test for two.
I'll close with this: The second bench test I posted on the other thread was not funded by any manufacturer and involved a somewhat more realistic "test" of the machines. The PR System One slightly outperformed the Resmed S9 in terms of reducing the both the overall AHI and the obstructive part of the AHI, although the difference was probably not statistically significant. And neither of these machines managed to reduce the AHI to below 5. But the authors do point out that these machines have their strengths and that if they had been tested with an appropriate min pressure setting
, then they probably would have been able to have brought the obstructive part of the AHI down below 5.