Interpreting Encore Mask Leak Data

Sleep_Depraved · Post by **Sleep_Depraved** » Fri Mar 21, 2008 5:21 pm

Hi,

Can someone please explain how to interpret Mask Leak data? I've found various aspects mentioned in individual comments, but the info is always fragmentary and never adds up to a complete picture that puts in context:

What do the measurements represent?
What defines a "large leak" from other leaks?
What are "good/acceptable" readings?
How do the various kinds of mask leaks affect/interact with other measurements?
What actions should be considered based on mask leak measurements?
etc.

I don't understand this variable well enough to even know what questions to ask. The other measurements all make sense to me... any help much appreciated...

Thanks in advance!

bdp522 · Post by **bdp522** » Fri Mar 21, 2008 7:59 pm

Masks have exhaust vents. These vents will have a set exhaust rate. Each mask comes with a little booklet or paper that shows the exhaust rates for that mask. Any thing over that rate is a leak. Leaks that are too high mean you aren't getting proper therapy. Resmed uses L/s and the machine gets set to the mask used, So anything over .40 would be something to worry about. Respironics lets us do the math. I use the CL2 at a pressure of 9.5, the exhaust rate is 27. If my leak data shows 30, I subtract 27 for a leak of 3. I think that a leak of more than 10 over the exhaust rate is too much and will affect therapy. I've read that once the leak hits 50, including the exhaust rate, the other data(AHI, etc) may be unreliable. You will also find that if you can control your leaks, you'll get better treatment.

Hope this helps

Brenda

jules · Post by **jules** » Fri Mar 21, 2008 8:06 pm

bdp522 wrote:Masks have exhaust vents. These vents will have a set exhaust rate. Each mask comes with a little booklet or paper that shows the exhaust rates for that mask. Any thing over that rate is a leak. Leaks that are too high mean you aren't getting proper therapy. Resmed uses L/s and the machine gets set to the mask used, So anything over .40 would be something to worry about. Respironics lets us do the math. I use the CL2 at a pressure of 9.5, the exhaust rate is 27. If my leak data shows 30, I subtract 27 for a leak of 3. I think that a leak of more than 10 over the exhaust rate is too much and will affect therapy. I've read that once the leak hits 50, including the exhaust rate, the other data(AHI, etc) may be unreliable. You will also find that if you can control your leaks, you'll get better treatment.

Hope this helps

Brenda

Respironics reports the exhuast plus leak total in encore pro. I would be worried about what the leak graph looks like.

Resmed reports the excess leak and yes, in that case one has to do the math. However, a leak of .40 on a Resmed is 24 L/min over what the mask in the mask settings allows. I would suspect that is excessive.

Although there are these charts in the pamphlets, masks don't always leak at those rates. If you look at Resmed's mask, they are plus/minus 6 L/min.

Hence the graphs of the leaks are more crucial, imho, than the actual numbers.

Sleep_Depraved · Post by **Sleep_Depraved** » Sat Mar 22, 2008 1:40 pm

Thanks for the info so far.

I'm still trying to get a handle on what I'm looking at...

What makes a chart "good" vs. "bad" and what can I do about it?

In my case, I'm using the Aura/Twilight/whatever which according to the pamphlet at my pressure range has an Flow Rate of 25-30 LPM. On some days Encore shows an average leak in the 30s, sometimes 40s, I had one last week in the 50s, but there was a lot of large leak that night.

What is this telling me? How should I factor it in when looking at other stats like AHI?

If I get up to pee in the middle of the night, how is this affecting the leak rate?

I'm sorry if these seem like basic questions, but I'm coming in on the ground floor and trying to make the best use of this info.

Thanks again!

RiverDave · Post by **RiverDave** » Sat Mar 22, 2008 2:13 pm

The goal is to keep your leak rate as close to the "pamphlet" leak rate as you can.

It's telling you how your mask is fitting - the higher the leak rate, the more work you need to do to stabilize the mask. Your treatment is also negatively affected by excessive leaks. Once your leak rate gets too excessive, the AHI reported by the machine could be wrong.

Turn the machine off when you go to the bathroom and restart it when you get back. If you just take the mask off or unplug with the machine running, the machine doesn't know you are not there and keeps recording erroneous data.