In support of archangle's points:
Burkebang wrote: . . . giving us only the pressure that is actually needed to treat events when they occur, . . . as wide pressure range as possible. . . .
That was the working theory behind the development of APAP, but in practice many patients have achieved lower home-machine-reported AHI--and, more important, more restful sleep--by raising their minimum. So when someone comes here with high AHI and not feeling rested when using an APAP, we pass on what has worked for us--raising the minimum pressure. It is surprising how many are helped by trying that.
. . . Low minimum pressures also makes many more people able to be compliant and tolerate the treatment. . . .
It is amazing how many doctors believe that. Doctors often think that since some find 20 cm difficult to tolerate, that must mean that the lower the pressure the better when it comes to any patient's tolerating treatment.
However, experienced users on this board have found that too
low of a pressure can actually be a bigger problem with comfort than the pressure being too high. Many patients feel starved for air at 4 cm and adjust to therapy much easier at 6 cm, or even 8 cm. Doctors don't know that because they've never used CPAP themselves. Fortunately, members of this board are here to pass on things that doctors have yet to understand about PAP therapy. Docs make assumptions about PAP therapy all the time that RTs have to explain to the docs are not so, and sometimes we as patients have to respectfully do the same. Even docs who know the science may not fully grasp the application and especially have little understanding of the comfort aspect of the treatment. Medically speaking, PAP therapy for OSA is new, so few docs understand the nuts and bolts of day-to-day treatment. That is true of CPAP, let alone APAP.
As has been said, if someone feels great and has reasonable AHI with his auto-titrating machine set wide open with a 4 cm minimum, that is great. Stick with what works. However, many have found that those constantly changing pressures are disruptive to their sleep and so have benefited greatly from raising their minimum pressure setting, even during ramp. It is worth a try to see if it helps. It is sort of a way to get the benefits of APAP and the benefits of CPAP at the same time--making it so the machine only rarely has to adjust the pressures so that disturbance to sleep is minimized.