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+--- Thread: Large Leaks (/Thread-Large-Leaks--42233)
Large Leaks - Opus1 - 11-19-2023
What is the significance of leaks that exceed 24 l/min (Resmed Airsense)?
What actually happens if that threshold is exceeded?
The only mention of "leaks" in the clinical manual is this:
Note: The use of a ResMed approved hypoallergenic filter will result in a
"small reduction in the accuracy of the delivered pressure at high leaks"
RE: Large Leaks - Jay51 - 11-19-2023
The first one, like you mentioned is accuracy. The higher the leak rate the less accuracy usually. And then there comes a certain point with a huge leak that the machine is pumping maximum air and it is not even producing much therapeutic benefit. The machines algorithms are calibrated to work best with no to low leaks (for both detecting events and delivering the correct therapeutic pressure(s). Through all of Resmed's testing, they have concluded that 24 L/min is the maximum allowable leak for their machines to appropriately function.
Arousals - waking up from mask farts and/or air blowing in the eyes is another consequence of very large leaks.
A third one I have seen is a slight increase in CA's (central apneas). I have seen some charts that when the leaks get really large, central apneas increase.
I, personally, have found putting effort into reducing leaks as small as possible to be a good investment in my therapy. Different masks can seal better to an individual's face (different people have different facial measurements, etc.). Or even nasal pillow masks can help, etc. There is variety is mask choice and style, but leaks (and comfort and performance) should be considered. Many people use mouth tape with nasal or nasal pillow masks. Strap tightness and position and even mask liners can help, too.
Mask Primer
RE: Large Leaks - Opus1 - 11-19-2023
to Jay51
Thanks for the link, really good information there (albeit seems a little dated).
Relative to leaks I'm experiencing, I'm not getting any noise (farting or kazoo-type), and have felt around the seal to see if I can "feel" any air escaping - none that I can detect - so I doubt that it's causing arousals.
My CAs are non-existent.
Nevertheless, my Large Leak % run 25 to 80 % (time over 24 threshold) when I look at the last month of OSCAR data.
What's left is the leaks are impacting the event or condition detection. I just can't imagine by how much. and in what direction. I'm not sure that I should take much comfort in Resmed's assertion of a "small reduction in accuracy".
BTW, I am an inveterate mouth breather. Too many broken noses - Ha.
RE: Large Leaks - Deborah K. - 11-20-2023
If you post an Oscar chart we will be much better able to help you.
RE: Large Leaks - Opus1 - 11-20-2023
Here you go:
[img]
![[Image: B2EBN1g.jpg]](https://i.imgur.com/B2EBN1g.jpg)
[/img]also, :
[img]
![[Image: SK0UP5a.jpg]](https://i.imgur.com/SK0UP5a.jpg)
[/img]
RE: Large Leaks - PeaceLoveAndPizza - 11-20-2023
Key point as Jay51 said, when the leaks are greater than 24 l/min therapy is impacted. For this chart ~60% of the time there was effectively no therapy and all bets are off during those windows. To say nothing of how it impacts sleep quality. With effectively a one-way air flow with some occasional occlusion, it is hard to trust anything reported during those windows except the leak rate.
If you are not leaking from the mask, then it is elsewhere, likely the hose, water chamber, or connectors.
RE: Large Leaks - SarcasticDave94 - 11-20-2023
Something to consider, the leak chart displayed here from the ResMed, if I have it correctly, means this leak is above the programmed intentional leaks needed for you to wear a mask and exhale. This 24 L/Min leak redline is meaning over this level, accuracy in therapy is questionable at best, most pressure is lost to leaks.
I'll mention a comparison from another thread: your CPAP is like a tire pump, you're trying to inflate a tire. Easy enough until you see there's a giant hole in the sidewall. The tire pump can attempt to pump the tire with a small leak but it's slower than designed. A large hole in the tire however means you're not getting it done.
Unfortunately your leak rate is approaching levels of no mask attached to the hose. Check all connections, humidifier, and seals.
RE: Large Leaks - Opus1 - 11-20-2023
I traded machine with my partner (main unit, humidifier, hose, and elbow), with the same result leak > 24 liters/min for 50% of the night. So no joy there.
I guess part of the question I'm asking is this: If Resmed considers a 20 l/m unintentional leak acceptable , to what degree is a 28 l/min unacceptable?
RE: Large Leaks - Jay51 - 11-20-2023
Fair question. To what degree is 28L/min unnacceptable? After 24 L/min therapy is a wash. It is most likely not effective or even calculated correctly.
The bigger picture seems to be this: your full face mask should not be leaking as much as it is with pressure only going to around 7 or so. IMO a different mask might save the day for you. Have you tried different strap tensions? Washed the oil off of the mask that can get on their from contact with your face. If you can't get any better results after lots of tries with this mask, a new one may be needed. I have several masks laying around that I tried that didn't work. It took several tries to get the right mask for me. Your facial contours may be different. If you want to, do some online research with different masks and their specs and reviews to try to find one that you think would work better. Supplier #1 here gives a 30 day trial on masks - you can exchange it for a different mask if that one doesn't work for you. There are different styles: nasal pillow masks, nasal cradle, hybrid full face masks that fit under the nose; and numerous different models of full face masks on the market.
RE: Large Leaks - UnicornRider - 11-20-2023
I found if I clean the mask daily with a mild soap and vinegar rinse with follow up water rinse, that got my leaks under control.