Leak rates, what's normal and does it change with mask type or brand?

[happydreams]

How does one know what is a normal leak rate for a mask?  It's obvious if one has a huge problem.  Definitely not obvious if one has a minor leak.  To be sure the machine can correct for minor leaks, but, why not fix the problem.  Does it differ by mask type and brand or machine?  Is there a list of expected leak rates for masks?

In OSCAR there's a setting to flag leaks.  At the moment, it's set to 16L/min.  I have no idea if it's too high, too low, or appropriate for a ResMed AirFit F10.  Or for that matter, a ResMed AirCurve 10 VAuto.  Furthermore, if I change the mask, perhaps the settings should change?

I'm asking these questions after a terrible nights sleep, so please forgive me if my questions are, well, kind of nonsensical.  Thanks.

[jaswilliams]

Happy dreams, a Resmed machine works out itself the vent flow rate and remove this intentional leak from the graphs any leak less than 24l/m and that is the default location for the red leak line is absolutely fine and the machine will compensate so your leaks of under 16 is even better

[SevereApnea]

One thing I noticed on my Resmed Autosense when using a Philips Dreamwear FFM was this.

Both Resmed and Oscar and ResScan said leaks were LOW over a few nights (0 - 6 L/min) but those were nights I was doing battle with the mask struggling to contain leaks. No way were they that low.

After my next visit to the Sleep Tech these were the notes I took:

About the Dreamwear, when I mentioned that the ResScan and even the Autosense say the leaks are very low or Zero, he said this is because the leak detection algorithm in the machine is calibrated for the ResMed masks, not the Philips ones! I thought so.

True or Not?


Acceptable leak rates are 
Relative to the Machine: if it can compensate for by increasing volume of air flow (<24 L/min for resmed).
Relative to You: to what you can tolerate, if it effects arousals, how if effects your therapy, etc.

Acceptable leak rates for me differ whether I am using a nasal or FFM. 
For me Zero leak with FFM is unacceptable.
Anything from 10 to 16 L/min seems OK.

[Dormeo]

I want to single out part of what SevereApnea wrote:

"Acceptable leak rates are
Relative to the Machine: if it can compensate for by increasing volume of air flow (<24 L/min for resmed).
Relative to You: to what you can tolerate, if it effects arousals, how if effects your therapy, etc."

This strikes me as exactly right. Your machine can detect events and deliver treatment when the leak rate is below 24. But if a leak wakes you up or keeps you awake, even if it is a tiny leak, it is a problem.

Be sure your machine has the right mask type setting for your mask. Other than that, I believe it doesn't matter what brand or type of mask you use.

You mention having a bad night. Is your mask the problem, do you think?

[happydreams]

I want to single out part of what SevereApnea wrote:

"Acceptable leak rates are
Relative to the Machine: if it can compensate for by increasing volume of air flow (<24 L/min for resmed).
Relative to You: to what you can tolerate, if it effects arousals, how if effects your therapy, etc."

This strikes me as exactly right.  Your machine can detect events and deliver treatment when the leak rate is below 24.  But if a leak wakes you up or keeps you awake, even if it is a tiny leak, it is a problem.

Be sure your  machine has the right mask type setting for your mask.  Other than that, I believe it doesn't matter what brand or type of mask you use.

You mention having a bad night.  Is your mask the problem, do you think?

It's possible.  The mask does leak into my eyes although the rate is very small.  However, it has been enough to have given me dry eye.  Never had the condition before PAP.   I'll try a different mask to reduce the leakage.  I'm apparently very sensitive to small leaks.  Definitely have had them wake me up.  However, first, I need to solve my machine settings.

My bad night was due to a new brand machine and settings.  Clobbered me with lots of CA's.  Second night was better.  Both nights the perceived and measured leakage was quite low.  I set my AirCurve 10 VAuto to FFM, as that was the only relevant setting.  

I was initially asking about leakage, because the amount of leakage a machine can compensate probably is brand dependent.  OSCAR doesn't explicitly take that into account, to my knowledge.  I changed the OSCAR leak rate setting in the past and was wondering how to set it back to an appropriate value.

[SarcasticDave94]

I'm thinking it's a right click of your mouse while pointing at the leak rate chart. Look for a red line or similar and change it to 24 L/Min. See if that helps.