What is a decent leak rate?

[Guest (MRH)]

I know that every mask has a inherant leak built into it, and there are charts showing what each mask has and at what pressure setting. My question is what is a acceptable leak above and the beyond the built in leak? Say your mask has a leak rate of 41lpm, would say 48 lpm still be ok, or even 50 lpm are there any guidlines?

Thanks again, this forum is great!!
Mark

[Goofproof]

At 41 LPM a mask would be useless for me, for good treatment I have to be 37 LPM or under. That's why the Hybrid would be useless to me. Jim

[Wulfman...]

Hi Mark.

The question(s) that you pose have some variables......like "That depends on...."

Whether you have software and the ability to monitor nightly statistics.
Whether you use a full face mask or nasal mask (you may be leaking air out your mouth when using a nasal mask).
Whether the leakage is in spikes (from moving around at night and skewing the mask) or if it's a constant higher number throughout the night (might indicate mouth leakage).
Whether you have a proper-fitting mask......too large, too small, too loose or too tight can affect the leakage numbers.
Whether you take off your mask before turning off your machine (I strongly recommend NOT doing that)

There are probably a number of others (and I have no experience with nasal masks), but those are some that occurred to me at the moment.

Generally speaking, if it's an occasional thing, a larger leak rate like the ones you mentioned are not a big deal. Many PAP machines can compensate for leakage and maintain the proper pressure levels.
If it's a consistent thing, then you need to investigate WHY.

Hope that helps.

Den

[SleepingBeauty]

Has anyone compiled a list of masks/leak rates? It would be handy to have one list. If they haven't, I'll volunteer to make one up if everyone wants to supply me with the stats.

[geoDoug]

Has anyone compiled a list of masks/leak rates? It would be handy to have one list. If they haven't, I'll volunteer to make one up if everyone wants to supply me with the stats.

This may be what you're looking for:
CPAP Mask Leak Rates. It's a collaborative effort that gives a pretty good idea for several masks.

Doug.

[MRH (guest)]

You guys are missing my question Here it is again I have a full face mask, my pressure is at 11 cm h20 and it is a Flexifit mask which lists the leak for the mask for my pressure at 41 lpm. So what is a acceptable leak above the 41 lpm? I have never seen any hard and fast numbers to go by. I know 0 leaks would be best but I don't think that will happen with the tossing and turning when I sleep. OH and I have the software to use to check things.


Thanks,
Mark

PS... Last night I had a 40.9 lpm leak avg even with spikes from leaks while moving around and leaking

[MRH]

Oops forgot to log in on the last post.

Mark

[Wulfman...]

You guys are missing my question Here it is again I have a full face mask, my pressure is at 11 cm h20 and it is a Flexifit mask which lists the leak for the mask for my pressure at 41 lpm. So what is a acceptable leak above the 41 lpm? I have never seen any hard and fast numbers to go by. I know 0 leaks would be best but I don't think that will happen with the tossing and turning when I sleep. OH and I have the software to use to check things.


Thanks,
Mark

PS... Last night I had a 40.9 lpm leak avg even with spikes from leaks while moving around and leaking

I don't think we missed (or misunderstood) the question.....it's just not a simple "Yes or No" answer as it depends on a multitude of circumstances.

Looks like you had a respectable leak rate last night.

One other thing..... Sometime in the last couple of years, I think I remember someone stating (or theorizing) that the logic in the Respironics machines (or more specifically the Encore Pro software) has a tendency to overlook some of the "spikes" when it generates the leak numbers. The spikes may show up more in the "Max Leak" figures.....which can be better seen in the MyEncore or Encore Pro Analyzer add-on programs. Those programs seem to report higher "Average Leak" and "Max Leak" numbers in those charts than Encore Pro and I think it may be for that reason. I've noticed that my "Max Leak" numbers will jump around on the chart for no apparent reason......even when I have somewhat normal "Average Leak" numbers.

Den

[Goofproof]

I checked back in my records in 2006, when I was using my FlexFit 431, (I stopped using if because of poorer treatment. At 15.5 CM I was AVGing mid 40's (45). I changed masks, but the most important thing I went to APAP which allowed me to use less pressure most of the night, meaning less leaks.

At that point in time I was using the ComfortFull also the leak rate compaired with the 431, but the treatment was better. (Lower AHI), with the ComfortFull. The last half of the night the 431 leaked a lot. Jim

[MRH]

Thanks guys for the answers, I guess I was looking for some hard numbers to go by. I do have the My Encore loaded but it never shows my leaks on the graph. And the Encore pro just has been showing the avg leaks and occasionally does it ever show a max leak. I just switched from the Comfortfull to the 431 due to leaks, and it not fitting well, made my gums bruised (I had it tight trying to stop leaks around my chin area) My numbers on the AHI, Hypopneas , and snores are better overall with the 431. Still not good yet though between 10 and 20 on AHI. So after I get some more data I am going to print it all out and see my PCP and see if maybe I should switch to APAP. Just taking baby steps I know I will get it there soon.

Mark

[Snoredog]

the leak formula is simple:

1. Find out your avg. 90% or CPAP pressure.
2. Find your current mask's "flow" rate from mfg supplied data card that comes with all masks, look up your pressure on that flow curve, find the "intentional" leak rate, usually shown in Liters per minute (L/m).
3. If at 10cm pressure that chart shows your exhaust leak rate to be 32L/m @ 10 cm pressure then if you are having Zero external leak, your leak rate should be 32L/m.

If your machine shows an avg. leak rate of 40L/m then you subtract your mask intentional leak (flow found on the chart) from that, so it would be:

1. Machine shows avg. leak = 40 L/m
2. Subtract the 32L/m from that = 8 L/m external leak.

Well how bad is that? That all depends, if we KNOW the algorithm on the machine may stop functioning with too much leak, such as on a Remstar at 75L/m, you can assume any data being displayed may also be skewed because the machine cannot handle the leak seen.

What we have seen over the years before machines started displaying leak on the LCD was that you were fine (therapy wise) if you kept your external leak below 20 L/m. If you have less than that, then hey great, on a Resmed with their star rating system the lower the external leak the more stars get displayed. They assume you are using one of their masks and have selected it from the LCD, all that does is tell the machine the mask's intentional leak rate in advance. If you punch in Mir Full it knows what the leak rate is for that mask, then it knows what its maximum leak it can compensate for (zero stars).

You are always going to have some external leak, the better you manage that external leak the better your therapy is and quieter your machine will be.

[MRH]

That was th answer I was after, the 20 lpm as a limit to be under. I am doing fine then, for the most part. I still can do better I am sure. The worst night so far since swithching masks, has been 9 lpm leak avg over the intended mask leak. That was about the best I had in the 2 months before of use on the old mask. I have been shaving every other night and making sure to wash my face trying to make the leaks better. Like I said baby steps but heading the right direction.

Thanks again,
Mark

[John_M]

Say your mask has a leak rate of 41lpm, would say 48 lpm still be ok, or even 50 lpm are there any guidlines?

Welcome Mark.

I love that question. I have been wondering about it for ages.

Here are the answers I have got so far. I admit ithey are not very satisfactory.

It is in the Sleep Apnea Wiki at Mask Leak Rate.

My residual lewak rate is about 12 lpm and I am trying to get it down.

John M

PS one of the difficulties is what to call it. Some people call it external, others accidental or resiudal. We are close to starting a flame war on its name

[geoDoug]

We are close to starting a flame war on its name

Foooooooooooooooooooood Fiiiiiiiiiiiiiiiiiiiiiiiiiight!!!!

[Slinky]

Hey, SnoreDog!!! Are you SURE "all" masks come w/their "intended leak rate" included in their literature???

I ask because the only Resmed mask I've tried is the Swift and there is NOTHING giving the "intended leak rates" in the Swift literature unless it is on the CD that comes w/it. I never bothered with the CD.