Pressure VS. Mask Type

oldgearhead · Post by **oldgearhead** » Fri May 26, 2006 11:48 am

I've noticed something, this week: Given the same pressure, say 8 cm/H2O,
my nasal pillow mask seems to deliver better results (I feel better), than
my UMFF. However, the UMFF at 10 cm/H2O is just fine, and it leaks less at 10 than 8??

Has anyone studied this? Is this still another reason to have an APAP?

My RemStar Auto should arrive early next week. I think I'll set it for 8-12 and keep a log of the mask type for each night. However, I think my data will be flawed, because my sleep doctor says my 'events' are positional.

I would like to know if the mask type plays a part in the determination of correct pressure.

littlebaddow · Post by **littlebaddow** » Fri May 26, 2006 12:13 pm

Whilst I can't say I've studied it, I think the answer is probably yes the mask is one of the factors that affects results.
I have 3 masks and over a period of around 18 months, the average AHI is 0.8 for the full face ultra (which I don't like but use when I have a cold), 1.2 for the mirage vista (my personal favourite) and 2.6 for the breeze nasal pillows (which I don't get on with).
I'm sure there will also be other factors, including sleep position, alcohol/food consumption etc that will also affect results so it may be that you can't draw too many conclusions from a short period.

WindFlyer · Post by **WindFlyer** » Fri May 26, 2006 1:48 pm

When it comes to mask size and pressure one should take into account Boyle's law that pressure varies inversely with volume. I've concluded this is why when I first started using the UMFF mask I was still snoring occasionally. Once the pressure was bumped up the problem went away. As a result of this I am stuck with a slightly higher pressure than necessary now when I use my nose mask, but that doesn't bother me as long as the therapy is effective.

oldgearhead · Post by **oldgearhead** » Fri May 26, 2006 2:03 pm

WindFlyer - I tried to use the same pressure for both the nasal pillow and
the UMFF, but I can't keep from 'blowing out' the mouth tape at the higher pressure with the nasal pillows, and I experienced snoring when trying to use the UMFF at the lower pressure. So, at least for now I'll change the pressure when I change the mask type. Furthermore, the UMFF seals better at 10 cm/H2O, than it does at 8 cm/H2O.

I'll try the UMFF this weekend at 9 cm/H2O, with the divers seal goop.

Machine	Mask