I just replaced an old Resmed S9 with a new Resmed AirSense 10. I've used a succession of Resmed autopaps since starting CPAP treatment based on advice that Resmed autopaps are better able to handle shallow breathing that is characteristic of allergy sufferers. After decades of CPAP use with Resmed machines, the AirSense 10 seems to behave differently regarding EPR.
EPR has been a feature since the S8. The AirSense 10 came preset to an EPR level of 2 and always active, which I believe is consistent with the previous machines. I've been using it for several weeks, and experiencing a problem I did not have with the previous machines.
At low pressures, like while falling asleep or waking at the end of a sleep cycle, I can breathe normally. However, I find myself awakening during periods when the pressure is at the "treatment" level. I notice that breathing is very shallow, ranging between my lungs being fully inflated and almost fully inflated. I have the urge to yawn, but can't because my lungs are already full. My chest feels like it's had a workout. I open my mouth to relieve the air pressure and can breathe normally through my mouth until I fall asleep again. I'm sleeping several hours longer than I did with the previous machines (10 hours), but waking up feeling like I still need more sleep. The symptoms are consistent with poor oxygen exchange due to lungs staying full of stale air.
I suppose it's possible that the machine is defective, or there has been some design change in this model making it less responsive to my breathing patterns than the previous models. I was just going to try bumping the EPR level to 3, but the page linked to at the beginning seems to indicate that the EPR behavior may be working "as designed", in which case it isn't clear what the solution might be.
That link and others describe EPR as being more of a "psychological" help than simulating the behavior of a bipap. EPR can be set to operate only while the machine is ramping up, so that breathing feels more normal while you're still awake. However, even if it's set to be on all the time, the linked article indicates that the machine temporarily stops EPR if it detects shallow breathing. The article refers to the S8, which would indicate that the behavior isn't new with the AirSense 10. The shallow breathing that triggers suspension of EPR appears to be exactly the problem with the new machine, and what I was looking to EPR to solve.
My apnea is during inhalation rather than exhalation, so I would not expect EPR to make it worse on that basis. I'm a shallow breather, which caused a problem with my very first cpap, and led me to Resmed machines. I've done well with prior Resmed machines; this is the first one with this problem.
Can anyone shed any light on the situation? Has there been a design change in the 10 which might make it no longer suitable for me? I don't want to just exchange it for another machine of the same model if that would be expected to behave the same.
Moderator Action: Link Removed