(07-05-2013, 11:45 AM)tokyo43 Wrote: What was the rationale behind turning off EPR?
I think, and I don't have any evidence to back this up, that pressure relief on exhale makes it harder for the respiratory system to adjust for some people; hence, some folks experience increased CAs. My rational for this is that with pressure relief on exhale, your system has to get used to the unnatural difference between pressure when you inhale and pressure when you exhale; whereas, without a pressure differential, your body just has to get used to higher pressure. Of course, the body can adapt - it just might take longer or be more problematic when the necessary adaptation is more complex.
Also, in regard to increased OAs, the pressure relief on exhale could possibly be allowing the airway to, ever so slightly, begin to close - which could then make it more difficult to keep the airway completely open (i.e. the pressure has to recover full splint, rather than just maintain full splint).
Anyway, that's just the way I rationalize it and it could very well be wrong.
Pressure relief may still be necessary for those who have a hard time adjusting to exhaling against the pressure and/or desirable to those who just have an easier time adjusting to the pressure differential; but, quite a few doctors have tightened up their policies on EPR and it is progressively being considered a part of therapy that has to be monitored and evaluated rather than just a comfort feature.