Pressure increase when Mask fit feature is used.

[Lukie]

When have my mask on and the machine running and turn on the mask check feature the pressure zooms up and it is a bit uncomfortable.
Is this normal? I do not use ramp and my starting night pressure is 6 and by morning it is up to 8 or 9.

[zonk]

The mask-fit pressure on Autoset (newer machines, not mine) based on 95th percentile pressure of the previous night or 10 whichever is greater

[trish6hundred]

Hi Lukie,
I think the mask fit feature gose up to a higher pressure as you are trying to fit your mask but if I'm not mistaken, the machine returns to a lower pressure in 3 minutes. I haven't used that feature in quite a while.
Hang in there for more responses to your post.

[Lukie]

It is kind of disconcerting to a new user. You put your mask on without ramp and want to check mask fit and whoosh a blast of air much higher than one's start pressure.

[trish6hundred]

Yes, it can be disconcerting when you aren't used to it or expecting it, that's for sure.

[zonk]

It is kind of disconcerting to a new user. You put your mask on without ramp and want to check mask fit and whoosh a blast of air much higher than one's start pressure.

It allows you adjust mask fit (cushion and headgear) at typical treatment pressure rather than at start pressure which is low if using APAP mode. On the other hand if mask fit is good at the lower start pressure than might spring a leak or two as pressure increases, its better to persevere a bit at the start and later collect the dividend in the form of better mask fit and sleep quality.
It goes for 3 minutes but you can terminate sooner pressing the push dial