leak data

i feel really dumb, but could someone PLEASE explain the leak data to me?
i've searched as much as my brain could handle and i sent a question to our host, but so far, nothing specific to my question...

honestly, talk to me like i'm two, because i have no idea what that data on the graphs or the summaries mean built in leak rate? average leak? percentages? large leak? i guess i should know this but i just don't...HELP!

For the Resmed machine I have, you program in the mask that you are using. The machine then factors in the exhaust rate so it is not a part of the leak rate. If your mask is perfectly sealed the leak rate will be zero. The software has a redline at a 40 leak rate.(that's so many liters per second or minute depending on your machine type) Anything above that makes it impossible to get effective treatment. However I have found leaks that are half of 40 can effect treatment negatively.
Some one will probably post a list of the exhaust rates of different masks and hopefully give you more info than I can on your particular machine.

I can help with part.

Built in leak rate is the design leak rate of the mask exaust port of the mask you are using. My NA II has a leak rate of 24 lts/sec at a pressure of 10 cm/h2o. Check the sheet that came with your mask.

Average Leak rate is the average leak (highs and lows divided by time)for the measured period. If you svbtract the built in leak rate from it it will tell you how much your mask leaked.

Large leak is a leak over 50 for 45 seconds ( I think)

Hi Sharon.

Listed below is a link to the rate chart that "DSM" (Doug) put together a year or two ago with data from the users of the various masks......and I've listed some links where "leak rates" have been discussed on the forum.

There SHOULD have been a "Vent Flow Rate" chart that came with your mask.
Each mask has "stated" rates at specific pressures. Any rate over that amount would be considered "leakage". Tossing and turning during the night can affect the numbers, so taking that into consideration can give some latitude to the numbers. It's another one of those situations where one has to look at trends rather than one night at a time.
I mostly just take note of the "average" leak amount from the Daily Details Report and if it looks "close", that's all I care about. For example, if my mask (UMFF) has a Vent Flow Rate of (about) 40 at a pressure of 12 cm, and the reports are within a few cm of that, I don't worry. Even if it gets up to 45 for a night or so, I don't worry. Like I said, having a restless night with a Large Leak can affect the numbers......so if I do have a Large Leak for a little bit, but the rest of the night looks pretty good on my leak line, I don't let it bother me. If, for example, my leak line would be all over the chart for several nights, then I'd start looking for the source of the problem.


http://www.internetage.com/cpapinfo/leak-rates-1.html

viewtopic.php?t=9187

viewtopic.php?t=19740

viewtopic.php?t=13494


Hope that helps. If you have more questions......fire away.

Den

.

thanks so much guys!

den, i'll be checking out those links, thanks again

sharon

ok so, the lowest pressure setting shown on the chart you linked me to, for the aura is 8, and the leak rate for that was 21

my first few nights on this machine looked like this, taken from nightly reports on encorepro analyzer:

sept. 27 pressure 6
max leak: 166 LPM
90% leak: 28.5 LPM
average leak: 25.0 LPM
large leak: 7.1 hours
(but i think the data for this first night is inaccurate; this was the day i picked it up and who knows how long the brainiac who set me up had it running before i got there; also, we spent some amount of time trying to figure out why the patient disconnect alert didn't go off with the aura)

sept. 28 pressure 6
max. leak: 144LPM
90% leak: 20.0 LPM
average leak: 19.0 LPM
large leak: 56 mins

sept. 29 pressure 6
max leak:165 LPM
90% leak: 22.0 LPM
average leak: 20.0 LPM
large leak: 0 secs.

sept. 30 pressure 7
max leak: 123 LPM
90% leak: 23.2 LPM
average leak: 21.2 LPM
large leak: 0 secs.

oct. 1 pressure 7
max leak: 95 LPM
90% leak: 22.0 LPM
average leak: 21.0 LPM
large leak: 5.6 hours

i guess i just don't understand how the numbers relate to each other...ie. if the average leak is around the same amount each night, how can there be such a big difference in the large leak numbers?
and what does the max leak number represent?

thanks guys...i'm getting there! one day, with your patient help i will have this stuff down and quit bugging you!

sharon

p.s. incidentally, the two nights with the higher pressure yielded higher AHI, especially OSA's

[quote="sharon1965"]ok so, the lowest pressure setting shown on the chart you linked me to, for the aura is 8, and the leak rate for that was 21

my first few nights on this machine looked like this, taken from nightly reports on encorepro analyzer:

sept. 27 pressure 6
max leak: 166 LPM
90% leak: 28.5 LPM
average leak: 25.0 LPM
large leak: 7.1 hours
(but i think the data for this first night is inaccurate; this was the day i picked it up and who knows how long the brainiac who set me up had it running before i got there; also, we spent some amount of time trying to figure out why the patient disconnect alert didn't go off with the aura)

sept. 28 pressure 6
max. leak: 144LPM
90% leak: 20.0 LPM
average leak: 19.0 LPM
large leak: 56 mins

sept. 29 pressure 6
max leak:165 LPM
90% leak: 22.0 LPM
average leak: 20.0 LPM
large leak: 0 secs.

sept. 30 pressure 7
max leak: 123 LPM
90% leak: 23.2 LPM
average leak: 21.2 LPM
large leak: 0 secs.

oct. 1 pressure 7
max leak: 95 LPM
90% leak: 22.0 LPM
average leak: 21.0 LPM
large leak: 5.6 hours

i guess i just don't understand how the numbers relate to each other...ie. if the average leak is around the same amount each night, how can there be such a big difference in the large leak numbers?
and what does the max leak number represent?

thanks guys...i'm getting there! one day, with your patient help i will have this stuff down and quit bugging you!

sharon

p.s. incidentally, the two nights with the higher pressure yielded higher AHI, especially OSA's