How different machines report their leak data

Someone has asked me to again clarify how the different brands of machines report their leak data.
It's in the SleepyHead tutorial thread but newbies don't know about it so they don't know to look there.
viewtopic/t88983/Pugsys-PointersSleepyH ... nding.html

We have had some not so new newbies commenting on really new newbies leak data and sometimes making it sound like the leaks are horrible when they aren't. This can cause unnecessary panic or stress and/or more work for someone like me or one of the other forum veterans when we have to go back and correct the error.

Mainly this is happening with ResMed S9 users and they are comparing their leak numbers to say someone who is using a Respironics PR System One machine. Different brands of machines report leaks differently and have different "large leak" lines in the sand so we have to be careful when we are commenting on a leak to make sure which machine is reporting that leak.

ResMed S9 users...your brand of machine is the only brand that reports excess leak only. Prior to calculating and reporting your leak numbers the machine subtracts an expected vent rate based on your pressure and your mask selection in the clinical menu.
So ResMed has decided that 24 L/min leak is their line in the sand to avoid.
Your 0.0 leak goal is something that I won't ever see with my Respironics machine because even if the excess leak is zero..my machine includes the vent/intentional leak rate in its calculations.

Respironics machines have always reported total leak....total leak is the mask's expected vent rate plus any excess leak and we are never given an exact number where our line in the sand is. From past experience seeing a lot of Respironics Encore reports (that will flag a large leak) it seems to be up around 85 to 90 L/min for the 50 series and older machines and around 75 to 80 L/min for 60 series machines. There may be a little more variation in the numbers when pressures used are very low but this is a close estimate based on seeing large leak flags at some numbers and not at other numbers that are just a little lower.
Example...with my old M series machine and the 50 series machines I never ever saw a large leak flag when I hit 85 L/min leak but I would see one at 90 L/min or above.
There have been a few rare reports of a large leak flag by a 50 series machine at around 75 L/min but those are really rare.
We have seen confirmation of large leak flags fairly often on the new 60 series machines at 75 L/min.
So that's the best guestimate that we can come up with.

So you ResMed users when you see a Respironics leak report number it is always going to be higher than your 24 L/min that you are told to avoid because of the fact that the Respironics machines report total leak and your S9 reports excess leak.
So apples and oranges comparison..doesn't work well.
So don't go telling me that my 30 L/min leak number is awfully high...it isn't. For me at my pressure with my mask's expected vent rate..that 30 L/min is really equal to zero excess leak. That's my mask's expected vent rate.

I know it's awfully confusing when you are new and trying to help another newbie to keep all this stuff sorted in your head.
This is one of the reasons we like to see the machine showing in the profile....We can glance at the machine and immediately know how that machine reports leaks. In time you newbies will be able to do the same. We learn new stuff all the time, myself included.

When I see a leak number I always check machine brand so that I know what is being reported..total leak or excess leak.
Then I can tell the person things have gone to the dogs or they are doing really well.
If they never get remotely close to large leak territory...their leaks are acceptable.
If they start skirting with with large leak territory or going over...then we check how long they were there. If half the night then that's a problem. If 15 minutes out of 7 hours of sleep...not the end of the world.

Side note...
Other brands and models have even different lines in the sand but still report total leak.
F & P Icon....65 L/min
F & P Sleepstyle series....90 to 95 L/min if I remember right
Devilibiss....95 L/min

and add to the list for short version list for large leak line in the sand
ResMed S9....24 L/min
ResMed S8....0.4 L/sec which if we multiply by 60 seconds gives us 24 L/min

Respironics PR System One 50 series....approx 85 to 90 L/min....also includes the M series and older models
Respironics PR System One 60 series...approx 75 to 80 L/min
When in doubt about PR S1 large leaks...Encore software will flag them so that they are easily seen...so if someone is pushing upwards close to these numbers in Sleepyhead....just use Encore to confirm if it was an official flag or not.

Also...when any leak (even tiny) is causing awkenings and fragmented sleep and messing with the mask...then that leak is unwanted even if it is tiny. Anything that messes with our sleep quality is unwanted and needs to be addressed.
These machines can compensate for a good bit of leak...that's why we have lines in the sand.

Sometimes my leak numbers and leak line look a bit ugly...sometimes they are picture perfect...since I sleep right through any leaks and it's rare that they go into large leak territory and stay there very long...I really don't care.
If the leaks woke me up then I would be worrying about them but since they don't then I don't care.
Now some people aren't happy unless they see a totally flat leak line and that's fine if that's what they have determined that they need to feel optimal but there are a lot of us out here doing quite well with some not so perfect leak numbers and leak lines.
This is another of those YMMV sticker situations.

Mask vent rates are normally included in the mask paperwork but in case you have lost your paperwork or looking for what someone else's mask's vent rate is...here's an old chart with some of the common masks and the pressures and vent rate. It's a bit old so missing some of the newer masks.
http://www.internetage.com/cpapinfo/leak-rates-1.html

Great synthesis of leak info, Pugsy!!

Here's a link to the chart that covers flow rates for most Resmed masks: http://www.resmed.com/us/assets/documen ... sa_eng.pdf