Why should I look at leak rate data ?

[liv2kite]

I am confused about how to think about leak rate data.

I have never thought of leak rate much at all or not thought of it as being reflective of therapeutic effectiveness. I have always considered leaks to be a mechanical property related to the mask and not the machine. I guess since you have to have a good seal to be getting the desired pressures, that eliminating leaks would be a pre-requisite to even beginning to consider evaluating the data to look for effectiveness of treatments (and to even consider the pressures indicated as being relevant). In other words, with leaks therapy will be sub-optimal and data will be junk, so worthless to evaluate data and better fix leak problem to optimize therapy. Is this correct ?

[Wulfman]

Correct.


Den

[DreamStalker]

Double correct.

[rested gal]

Triple correct.

Laura
__________________

Of interest:

"Question About Mouth Leak" -- topic started Sept 2008 by eLPete
viewtopic.php?p=299480#p299480

"What a DME company can do to be better!" -- topic started Mar 2010 by kevincoop
viewtopic.php?p=465052#p465052

[Mary Z]

You've got it right, though stopping or decreasing leaks is not necessarily easy. My doc stresses getting leaks under control.
Good luck

[ldj325]

I've had the S9 AutoSet for about 6 weeks now. I always check my "mask fit" before starting therapy and usually have no problems getting a good fit. For the 6 weeks my leaks are usually reported as 0.0. For some reason the past 2-3 nights the fit has not been good at the higher pressures of the mask fit. As my average pressure is usually reported as around 6.8 I decided to not worry about it and just went to sleep. This morning the leak rate was reported as 9.9 and my pressure had jumped to 8.2 with AHI of 2.2. I was under the impression that the S9 compensated for or took into account the leak rate effects on data, and that 9.9 is an acceptable leak rate. Is my data "flawed" because of that leak rate?

[Janknitz]

EVERY mask has a certain leak rate--if nothing else it has to account for the air being vented out. The larger manufacturers have charts on their websites and in their literature which tell you the acceptable leak rate for each mask at each pressure. Data capable machines should be able to differentiate between acceptable leak rates and unacceptable ones.

It's uncontrolled leaks over and above that accptable amount that are the problem. Some auto machines can compensate to a point and you can see that reflected in the data, but when the leak rates get too high, then the data gets skewed.

When people have overly high AHI's the first thing to do is look at leak rates. You are not getting effective therapy when the mask is leaking more than its built-in tolerance. But the leak may still not be enough to cause a lot of noise and sensation of leaking, so without data you may be unaware of the problem. That's why leak rate data can be so helpful.

[PST]

I would not dream of taking issue with an answer that has been triple dittoed, and I don't. However, I think it is possible to exaggerate the effect of leaks on therapy. As others have noted, all masks have an intentional vent rate, which is a kind of planned leak. Flow generators have enough extra power to push sufficient air to handle moderate leaks beyond the vent rate and adjust themselves accordingly. With the ResScan software, you can check on a CPAP machine and be sure that the proper pressure is maintained all night. Maybe that's more difficult on an autoset machine, since the intended pressure varies. On my S8 Elite II, it takes something really impressive, like failing to close the humidifier until it clicks, to create a leak so big that it actually makes the pressure graph dip. For small leaks the bigger danger is irritating the eyes, since that tends to be a place where air often squirts out. I also have a problem with irritating the wife, since I sometimes get little leaks that make a squealing noise. That's even more dangerous. There is no doubt that leaks are bad, but I think most people are still getting the benefit of their therapy even when they haven't yet conquered their leaks.

[dsm]

Re original post - Quadruple correct

Over a long period of time, I have come to regard leaks as highly detrimental to overall well being.

Each time there has been a period where daytime sleepiness was returning, I'd check my leak
data & see it was extra high. Sometimes trying to stop leaks proved very difficult, that was
until Karen (pad-a-cheek) introduced her anti-leak strap. That small strap seems to stabilize
the mask & keeps my leak data to a minimum compared to before.

Leak data provided by any machine is at best a 'guesstimate' and it appears that the greater
the leak, the less accurate the guesstimate seems to be. I suspect that nasal prongs provide
the more accurate leak data when compared to a full face mask.

DSM

[Velbor]

Despite quadruple agreement from some very knowledgeable and experienced posters, I would interject a note of caution. To paraphrase a comment I made in my CPAP Wiki article, "While .... leak is never desirable, care must be taken to avoid arbitrarily labeling it as terrible."

Mask Leaks: wiki/index.php/Mask_Leaks

The title / question of this thread, "Why should I look at leak rate data?" answers itself. Without data, you can't KNOW whether or not leak is significant (and actionable).

I would also reference another of my prior posts:

Leak: What the Manufacturers Say: viewtopic.php?f=1&t=41964

As I conclude in the Wiki article, "Leak is not a problem unless it is a problem. Otherwise, it’s just another four-letter word."

[dtsm]

I've been getting much higher leak rate the last 7-10 days. This is with a new Headrest that I've been trying out.Not exactly sure why.....my mouth is taped shut but I still get dry cotton mouth each morning. What's curious is:

1. my Ai remain consistently <1.5-2.0, sometimes <1.0
2. my pressure (set from 10.4 to 13) remains fairly stable, 95th around 11.5

So while I agree with all that getting as flat a leak line is critical, mine has been flying all over the charts but I feel fine

[PST]

That wiki article Velbor mentioned is terrific. That's where I'm going next time I have a question about leaks.

Mask Leaks: wiki/index.php/Mask_Leaks

[liv2kite]

Despite quadruple agreement from some very knowledgeable and experienced posters, I would interject a note of caution. To paraphrase a comment I made in my CPAP Wiki article, "While .... leak is never desirable, care must be taken to avoid arbitrarily labeling it as terrible."

Mask Leaks: wiki/index.php/Mask_Leaks

The title / question of this thread, "Why should I look at leak rate data?" answers itself. Without data, you can't KNOW whether or not leak is significant (and actionable).

I would also reference another of my prior posts:

Leak: What the Manufacturers Say: viewtopic.php?f=1&t=41964

As I conclude in the Wiki article, "Leak is not a problem unless it is a problem. Otherwise, it’s just another four-letter word."

Thank you. Very useful post and references. I am a convert: I will think about leaks but not worry about them too much necessarily. The wiki article is excellent.