Exhaust flow with ResMed Quattro mask

I just switched to a ResMed Quattro full-face mask, using a ResMed S8 Autoset. The mask fit seems fine. However, if I run the automated "mask fitting" test, with the mask setting at "full face," it reports a "poor" fit. I suspect that this is due to a pretty high flow rate through the exhaust ports at the bridge of the nose. Is this anything I should worry about? Is there some other setting I should be using?

I would say there might be two things at work here. If you are sure you have a good fit and there are no leaks, then the fitting evaluation portion of your machine may be faulty. The other alternative could be that you have leaks that you are not recognizing (maybe due to the high exhaust which is up by your eyes and the bridge of your nose.)

I am using the Resmed Autoset II and the Quattro FFM, too. I have 0.0 L/s from my mask and the fitting reading says it is excellent. It took me a good while to get to that reading (I had to keep tightening and adjusting the forehead dial) but I finally got there. I now have headgear strap marks in the back of my neck for a couple of hours after I get up each morning and a red indent on the bridge of my nose, by my mask no longer leaks and I am resting better.

Duke,

Go up to the forum Search function and put in the word "Teflon" and see if there's anything in those post/threads that will help with your Quattro mask. Those masks do better when not worn too tightly. The seals need to expand from the pressure inside the mask to fit the face, too.

Den

Thanks for the inputs, especially mdbarthe. With some further tightening of the straps and fiddling with the adjustment knob, I can now get the mask fit up to "excellent" most of the time. I guess it has to do with the knob changing the fit of the seal around the bridge of the nose.

Does anyone know what changing the mask type on the control panel actually does? I assume the software must use this info somehow.

The ResMeds have a built in leak rate table. You select the appropriate mask and the machine will subtract out the design(or intentional or whatever the correct word is) leak rate and report only the "bad" leak rate (the one you want to keep as close to zero as possible) on the LCD or software display.

DukeBedford wrote:I just switched to a ResMed Quattro full-face mask, using a ResMed S8 Autoset. The mask fit seems fine. However, if I run the automated "mask fitting" test, with the mask setting at "full face," it reports a "poor" fit. I suspect that this is due to a pretty high flow rate through the exhaust ports at the bridge of the nose. Is this anything I should worry about? Is there some other setting I should be using?

Part of the problem here is that you are likely viewing the LCD and conducting this test while in a vertical position, but keep in mind that when you go horizontal to sleep that gravity will change the shape of your face and thus the mask fit.

I don't bother with the mask fit feature but rather when in horizontal position...

-I will lift the mask up off my face and settle it back down.
-I will listen for air leaking.
-I will run my fingers along the edges of the mask to feel for a leak.
-I will open my eyes and if there is a leak around that area will feel it.

If a leak is detected I will readjust the mask.

I don't have the consistently ZERO readings that MD has... but they are well within acceptable limits most evenings. I also figure getting the pressure right is part of the mask fitting. Needlessly high pressure will make getting a good mask fit increasingly difficult.