Leaks Quattro Air - latest graph - question

[library lady]

Well, last night I had my best AHI since starting this journey on Feb. 3; it can't get much better! I'm still confused about Quattro Air leak rate, and which line is which in Sleepyhead. I'm thinking, from all that I've learned here, that the leak rate to be looking at is the bottom line, and the top line is actually total leak, which includes the allowance for intentional leak. I've scoured the manuals that came with the machine and the mask, and can't find anything.
Edit: I didn't get the AHI on this: It was .58. The graph wasn't small enough.. AHI flatlined from 6:30 on or whatever time shows in the graph, some leaks did occur during that time, the largest was at 33.
Data from 3-16-14:

[Pugsy]

Top line is Total Leak line which includes the intentional leak/vent rate.

The bottom line would be a close approximation to the excess only leak. Mark (Sleepyhead creator) had difficulty coming up with calculations for allowing for variable pressures when reporting excess leak only. As you know when your pressure increases the vent rate also increases. Mark wasn't able to polish the excess leak only reporting as much as he would like but it is likely very close.
So we mainly look at total leak because we are never given what would be a large leak when reporting only excess leak.

If you were to use Encore software you could see if those times you were pushing 90 L/min would be considered worthy of large leak flag...you are very close to it at times.
SleepyHead doesn't flag the large leak times. Instead we have to figure out where large leak territory begins and as long as we don't go above it, or minimally above it for short period of time...we estimate...or use Encore to know for sure.

Respironics never tells us exactly where large leak territory begins because it varies between mask used, pressure used and even machine. Past experience though has shown that it's up around 80 to 90 L/min total leak.

They also never tell us anything about where excess only leak might be too large.
Since past experience is a bit easier to see and understand we pretty much stick with Total Leak to understand first.
Excess leak...to be honest I rarely even look at it because I am so used to doing Total Leak as it is easier to evaluate.

When it comes down to it...assuming leaks don't wake you up...it doesn't really matter what the exact vent rate is as long as you stay below large leak territory.

[library lady]

Thank you Pugsy. The leaks actually don't bother me much any more. I sleep through most of them now, but I'm aware that large leaks, especially if there are lots of them, can impact the effectiveness of the therapy, so I always look at it and try to determine how to minimize them. Like you, I figure if I'm getting good sleep, and my AHI is where it should be, that's what matters. an interesting trend I've noticed as I look at the charts is that every night I typically wake up around 2:30 or 3 needing water and sometimes a potty trip. That darned cotton mouth! I have a big covered mug with a built-in straw that I keep on a little stool a few steps away from the bed where a spill won't impact the machine. I can walk to it, and by taking the elbow/vent off I can drink without taking the mask off. If I remember to do it, I turn the machine off, but when I forget I am reminded of it in the morning when I see the vertical line that goes up off the chart... maybe I will learn to remember!

[Pugsy]

You know you can look on the machine's LCD screen to see how much time might have been spent in large leak...
it gets reported as % of time in large leak...if the % is small or 0.0...then you didn't spend much if any time in large leak.

[John Chowder]

Hmm, I have the same mask but am averaging around 50 total leak rate (probably cause of that gel liner you sent me ) I'm not sure what a normal range is but as long as you're feeling rested it sounds like you should be good.

[library lady]

So that liner is working for you then?

[John Chowder]

Yes, it's working great for mask leak. There is an annoying scent that does not seem to be going away though. The packaging said a few days but I've been using this about a week and it's still there. For leaks though it's doing the job.

[CPAP Seal]

John Chowder:

We have the new version now of the Gel Liner. If scent of the old version bothers you please contact us at cpapseal.

(Sorry we rarely visit the forum so we just saw your comment from last month.)

Thank you
CPAPSeal Team

[old dude]

This may or may not be helpful but I've been using the Quattro Air for about 8 months now, and when my seal is fairly new my total leak rate in Encore Basic runs around 29-31. As the seal starts to wear a bit the leak rate goes up to around 32-34. That's as high as it ever gets for me, with pressures of 11/7.

I have given up trying to use the leak lines in SH except to get an idea of the relative "choppiness" of my leaks in any given night. For me it's much easier just to look at a single number in EB and be done with it.

By the way, the last time I looked Respironics listed the intentional leak number for similar masks at around 40 or so at my pressure. They didn't show the Quattro Air specifically so one had to guess and interpolate a bit.

[Jay Aitchsee]

Resmed mask flow rates, including Quattro Air:
http://www.resmed.com/assets/documents/ ... er_eng.pdf