Large Leak (LL)

[JackieLee]

it seems that my best numbers using pillows came, not 'every time' but more than not, when I had my machine on nasal, as opposed to pillows.

Is there anything to that, or was it just happenstance?

Actually probably not just happenstance. The choice in mask type menu can affect the baseline vent/leak rate that the machine uses to help it figure out what gets reported as excess leak baseline but it won't make a huge difference or enough to make much of an error in leak reported.
I don't know the exact numbers involved but there is a slight difference with each choice.
Example I have used (tried and hated it) a full face mask with a mask type choice of "pillows" and then realized my error and changed it but the actual leak report only changed maybe 2 L/min. Not enough to be that big of a deal.

Nasal pillows will have the least amount of baseline vent/leak allowed and full face mask choice will have the greatest allowance. We are talking small difference here. The "nasal" mask choice has something in between full face and pillows choice. Using nasal pillows with a "nasal" choice will maybe give you a slightly lower leak number than using pillows choice but unless you are having a LOT of excess leak it won't change it all that much.

But that's why your numbers were a little better with the nasal choice. The machine was using the slightly higher baseline leak as the number to compute excess leak. Remember ResMed machines report excess leak only after the baseline vent rate has been deducted. Other machines might report total leak which is the mask's expected vent rate plus any excess leak.

Clear as mud??? Not a deal breaker though to use nasal pillows with "nasal" as the mask menu choice. Close enough for government work.

Understood. I'll give it a go tonight. I switched the setting back to 7-9 pressure and had a lot more substantial 'above the llne' leaks as you referred to, however I had the pressure 7-9 for several nights in the recent past with decent numbers but also noticed the 'nasal' setting.