What is Normal Average Leak Rate?

I am trying to figure out if my leak rate is ok as compared to all the other data I'm getting. I have an Apex XT Auto and use an Apex Wizard 210 nasal mask. I am using Apex Easy Compliance software. What I am showing is the average for 22 days.

Average AHI: 2.27
Average Pressure: 8.2
Average 90th Percentile Pressure: 8.9
Average Leaks: 51.8
Average Time with Large Leak: 1.81 Minutes

My mask exhaust flow is about 24 L/minute at pressure 8.

If you subtract 24 l/m from 51.8 you come up with 27.8. I am not sure if this is how to figure this out or not but I have seen mentioned in different places that if your Average Leak Rate is around 25 you're ok.

Can anyone verify this and explain this so I know i'm getting proper therapy?

Thanx

lanco wrote:If you subtract 24 l/m from 51.8 you come up with 27.8. I am not sure if this is how to figure this out or not but I have seen mentioned in different places that if your Average Leak Rate is around 25 you're ok.

Sounds like you are using ResMed leak numbers and they aren't necessarily what you should be using with your machine since it isn't a ResMed machine.

lanco wrote:Average Time with Large Leak: 1.81 Minutes

Less than 2 minutes in large leaks is well within acceptable limits. This would be enough for me to be happy with leak situation as long as the leaks didn't wake me up. I wouldn't mess with worrying about the vent rate vs excess leak calculations. Let the machine do it for you.

Sounds like your machine reports total leak like the Respironics machines.
And thus hard to pinpoint an exact leak number where you should start being concerned.
If you want to use ResMed number as a guide it won't hurt anything but it is likely on the conservative side for your machine. I suspect that you have more room than that before large leak gets flagged.

Pugsy wrote:

lanco wrote:If you subtract 24 l/m from 51.8 you come up with 27.8. I am not sure if this is how to figure this out or not but I have seen mentioned in different places that if your Average Leak Rate is around 25 you're ok.

Sounds like you are using ResMed leak numbers and they aren't necessarily what you should be using with your machine since it isn't a ResMed machine..

I think lanco is just referrering to the intentional vent rate, (which actually, according to the manual would be around 24lpm), and not referring to the resmed number for excessive leaks (24lpm).

edit: corrected numbers.

palerider wrote:

Pugsy wrote:

lanco wrote:If you subtract 24 l/m from 51.8 you come up with 27.8. I am not sure if this is how to figure this out or not but I have seen mentioned in different places that if your Average Leak Rate is around 25 you're ok.

Sounds like you are using ResMed leak numbers and they aren't necessarily what you should be using with your machine since it isn't a ResMed machine..

I think lanco is just guessing at the intentional vent rate, (which actually, according to the manual would be around 28lpm, not 24lpm, and not referring to the resmed number for excessive leaks (24lpm).

As I said "My mask exhaust flow is about 24 L/minute at pressure 8." :This is according to the chart that comes with my face mask. I really think that someone that knows what all the stats mean that I gave will have more than enough to figure this out. I may be wrong.

Below is what my respiratory therapist said when I questioned all the leaks. Average being around 50 l/m Highest Leak being 74 and Lowest Leak being 7:

"If your total AHI is 2.23 then that is acceptable. I wouldn't overthink this too much. Regardless of the leak, if your AHI is that low, then you are good. Textbook normal is less than 5."

I am only a bit insecure about this because the original data I sent him showed a low AHI like around 1.75 at that time but leak rate similar to what I have listed here. Following that he is telling me to get a chin strap and then maybe a full face mask.

Then he told me that all was ok after resubmitting the newer info. I assume he missed the AHI number in the first correspondence and then corrected, but not sure and am a bit insecure because of how this played out.

Comments?

lanco wrote:As I said "My mask exhaust flow is about 24 L/minute at pressure 8." :This is according to the chart that comes with my face mask. I really think that someone that knows what all the stats mean that I gave will have more than enough to figure this out. I may be wrong.

yup, you're right, sorry about that, I pulled up the 220 manual without realizing it.

now, as far as what your machine, which is practically unknown here'bouts, considers unacceptable leaks, you'd have to tell us.

your machine is pretty much unknown here, so you'll find few with experience with it and able to speak confidently about how it behaves.

other machines, however, lose the ability to differentiate what types of apneas one is experiencing (if yours even does that) at high leak rates, and eventually loses the ability to even sense that you're having apneas or hypopneas, so, your doctor is taking an overly simplistic view of things.

controlled leaks and a low AHI are a good sign, wildly uncontrolled leaks throw everything into question.

what is wildly uncontrolled on your machine? I don't know. different machines handle the issue differently.

If someone could actually see a leak graph they might be able to spot where large leak territory begins.
Like when I was using my Respironics machine and wouldn't get a large leak flag when total leak (vent rate plus excess) hit 85 but I would get one when it hit 90 L/min (for my mask at my pressure).
So I was able to figure out approx where large leak territory began with my machine.

Without something to go on about all you can do is trust the time spent in large leak...and assume that up to large leak the machine is able to deal with things.

Unless you spend a prolonged period of time in large leak your AHI is going to be accurate.
Minor fluctuations in the AHI are a normal part of therapy so don't assume that the changes in AHI are related to leak unless you see a whole lot of minutes in large leak.
Less than 2 minutes in large leak doesn't even earn a second glance IMHO.

Perhaps this will help:

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We know that 74.0 is in large leak territory since it says you spent 1.8 minutes in large leak territory.
You need to look at other reports and look at the maximum and then look to see if it says you were in large leak territory at that maximum and maybe work backwards to find where the line in the sand is.
Example...if you have a report where the maximum was 60 L/min and it says no time in large leak...then you know that the line where large leak territory begins is somewhere between 60 and 74 L/min.
If you see a report where the max leak hit was 68 and still no time in large leak...then somewhere between 68 and 74. Or if you have one where the max is 65 and and still says you had some time in large leak then you know that it's going to have to be lower than 65.

I am totally unfamiliar with the software reports that your machine provides. Sorry but I can't help much.

Personally...I would just look at the time in large leak and if it isn't very much then I wouldn't worry about it. That's all I do now even with software reports that I am totally familiar with.

another reason not to want photobucket, big in your face "WANT TO GET RID OF THIS AD? PAY US MONEY"

I have been faithfully reading posts and trying to figure out leak rates and particularly all things dreamwear and so I am very interested in this thread.

I really don't want to face the possibility that my relatively good AHI are completely irrelevant because my leak rate is so awful. I dread admitting that I may be failing at using my dreamwear mask that is 1000 times better for me than the first ESON nasal mask which was really awful for me.

I also have still not learned how to post my my results and even with almost three months of results to chose from, I am not certain of a real pattern that I could post and say *THIS* is a representative day.

I'm a mess.
I'm sorry.
I'm still at a stage where I want help but can't really ask for it or completely understand the answers.

I think I have a more common machine that OP, lanco, so that may make things easier with regard to this threads topic question?

Do you guys think my AHI's are meaningless because of my leaks?
(note: I am *FEELING* better and I am really bonding to the therapy and believing CPAP (and CPAPTALK) is a part of my recovery)

AHI last night 1.95 last week 1.57 last month 1.86 since I began in May 2.75
Average Leak Rate 25.67 24.30 25.04 25.22
% of time above 57.03% 50.22% 48.36% 48.68%
Leak Rate threshold

Grace~~~ wrote:Do you guys think my AHI's are meaningless because of my leaks?

No, not meaningless but questionable during the time you are in large leak.
If half the night is in large leak...that part is questionable.
The other half not in large leak will be accurate.
Now how questionable the time in large leak actually is will depend on how far you go into large leak territory. The further you go the iffier it gets. If the bulk of the large leak time is spent below 30 L/min then the AHI is going to be fairly accurate. ResMed machines start losing the ability to sense, record and respond when the leaks go past 30 L/min...over 35 and they are pretty much clueless.

So the AHI during the half of the night when you weren't in large leak...that's accurate.
The AHI during the half of the night where you were in large leak...how accurate depends on how deep into large leak territory you went during the time of large leak. If you just barely went past 24 L/min the AHI will be accurate.

Pugsy wrote: If the bulk of the large leak time is spent below 30 L/min then the AHI is going to be fairly accurate. ResMed machines start losing the ability to sense, record and respond when the leaks go past 30 L/min...over 35 and they are pretty much clueless.

So the AHI during the half of the night when you weren't in large leak...that's accurate.
The AHI during the half of the night where you were in large leak...how accurate depends on how deep into large leak territory you went during the time of large leak. If you just barely went past 24 L/min the AHI will be accurate.

Pugsy, where do I find the L/ min in sleepyhead?
Statistics? Daily?
On a graph?

is the L / min the same as the "Average Leak Rate"?