Different mask, different pressure??

[gtaro]

I've been on CPAP for a number of years, using a nasal mask. Every so often, I experiment with a new full face mask. When I do, I've noticed my AHI doubles. Is the pressure delivered so differently with a full face mask that it affects performance? Or is there something else at work here?

[Pugsy]

First suspect might be leaks. Full face masks simply have a greater chance of leaking which of course can impact overall therapy effectiveness.
Second...in theory X amount of pressure should have the same effectiveness no matter which mask is used as long as leaks are well controlled but I have seen reports where some people do need more pressure when using a full face mack compared to nasal mask and the leaks aren't out of line. So the theory doesn't always translate into real life.
So you wouldn't be the first to report that you seem to need more pressure with a full face mask than you do with nasal mask. One person comes to mind and he needed 17 cm cpap pressure to keep obstructive events controlled using FFM and was able to actually get better control using nasal pillow mask and pressure at 15 cm cpap.

I use nasal pillow mask myself and have never used a full face mask so I can't confirm based on any personal experience.
I just know that it happens...it shouldn't but it does for some people. Not all people but some.

[gtaro]

Thanks Pugsy. I appreciate the response.