(01-19-2016, 12:21 PM)bazder Wrote: Phillips Respironics has a .pdf giving intentional leak rates for different masks but I'm not allowed to post links here yet. If I understood it correctly I think they estimate about 28L/min for the Amara View mask.
So, for instance, if my AirSense 10 AutoSet says my leak rate = 32L/min at pressure 12.3 what is the actual leak rate? Would it really be more like 32 - (~28) = ~4L/min and would that be OK even though the AirSense says "red frowny face" for mask leakage?
I'll send the link when I'm allowed ...
First, vent rate is proportional to pressure. Your mask vents 28 LPM at 4 cm-H2
O. At 12 cm-H2
O, it vents about 50 LPM.
Then, ResMed machines report unintended leak rate.
i.e. -- they subtract calculated vent rate and report that.
So, if it reports 32 LPM at 12 cm-H2
O, that is the Total minus (let's use my ResMed FFM as the standard) the 41 LPM vent rate for my mask.
At 12 cm-H2
O, there is a delta of 9 LPM in the vent rates of the two masks. ergo, the ResMed machine may overestimate true leakage by 9 LPM at 12 cm-H2
Using that delta of 9 LPM, let's correct the calculated leak rate for your mask at 12 cm-H2
O. 32 LPM (reported) - 9 LPM delta = 23 LPM calculated actual leak rate.
But, the machine sees 32 as the leakage; and you do not get a smiley face. Plus, with the extra 9 LPM, the blower unit may not be able to keep up the pressure.
That's why I strongly urge you to use software to see what the actual pressure is during times of reported Large Leak. And for you, I would suggest ResScan.