Major Mask Leaks and Impact on AHI

[kismet1]

I have been using my CPAP machine for 2 months and have consistently had AHI numbers below 1.0. However, I have been getting major leaks showing on Sleepy Head that have gone as high as 24% while my AHI numbers have remained low. Should I be concerned about the leaks if my AHI numbers remain low? Do major leaks prevent the machine from detecting AHIs - are my low AHI numbers erroneous because of the high number of majoy leaks? Also my leaks seem to be intermittent - have major leaks during a period of an hour or so and then the leaks disappear for the rest of the night. Is this a sign of mouth breathing?

Thanks!
CPAP: Resmed AirSense 10 for Her
Autoset
Minimum pressure 6 cmH2O
Maximum pressure 20 cmH2O
Humidifier setting at 7
Pressure range 6.0 - 12.5 cmH2O
Avg Pressure 9.07 cmH2O

Mask: Resmed AirFit N20 Nasal Mask

[Pugsy]

n Sleepy Head that have gone as high as 24% while my AHI numbers have remained low.

First of all where are you getting the 24 number....is it the time over red line % in the statistics or is it the 95% number column in the statistics?

When you say "as high as" I am thinking that you are talking about the 95% number and not the threshold % number.
The 95% number isn't a % number it's a L/min number and if the worst it ever is happens to be 24 L/min then you DON'T have leak issues enough to impact the AHI.
First you have to understand the definition of a 95% number...it means at OR BELOW that number for 95% of the night. It is not an overall average and it is not where you spent 95% of the night. The "OR BELOW" part of the definition is very important.

In terms of accuracy of the data reported when faced with large leaks over 24 L/min....only the time over 24 L/min comes into question so even if someone had 15 minutes with a 40 L/min leak...only the small portion during the large leak is impacted and 15 minutes out of a 7 hour night isn't going to make much of a difference with the numbers of anything. It's too small of a piece of the night.

Resmed gives us the 24 L/min number...it's a very conservative number and things do go straight into the toilet at 1 or 2 or 3 or even more above that line. It goes in the toilet very gradually.
From my own past experience with varying degrees of leaks and a night where I had a nice progression from little to really big I have found that between 24 to 30 L/min leak doesn't really seem to impact things all that much. From 30 to 35 things start getting a bit iffy and I start seeing green unknown flags where previously there were OA or hyponea flags. The leaks are affecting the machine's ability to figure out what is going on...it knows something is going on but can't figure out what so it get a green unknown flag.
Over 35 L/min thing start getting more iffy....and maybe the machine is actually missing events and the further past 35 I went the worse it was..

Now do I sometimes hit 45 L/min leak...sure I do. It's never for very long...maybe 5 minutes but the data is only questionable for those 5 minutes. It doesn't make the entire night's worth of data questionable. Even if I had 1 apnea even a minute during those 5 minutes that the machine missed it wouldn't really affect my AHI all that much if they had been flagged.

Now if you are seeing the 24% time over red line statistic and not the 95% number...we need to have a different discussion and maybe look at how high it is going and probably look at some detailed reports. 24 % doesn't earn Mr Frowny but it's more large leak than I would want to see on a consistent basis. But before turning on panic mode need to see just how long it spent in large leak and how deep it went.

[Pugsy]

Also my leaks seem to be intermittent - have major leaks during a period of an hour or so and then the leaks disappear for the rest of the night. Is this a sign of mouth breathing?

Could be mouth breathing but also could simply be mask movement. It's really pretty much impossible to tell one from the other on the detailed reports unless you have your mouth taped and you still get big leaks and since the tape has sealed the mouth the only thing left is mask movement.

Here's a good example of mask movement that could maybe be interpreted as mouth breathing because I use a nasal pillow mask.
The only thing is...these were with my mouth taped and the tape was secure in the AM...didn't come off.
These big leaks were all mask movement...new mask and trying different things and still getting large leaks so I wanted to make sure that the big leaks weren't mouth breathing because the fixes are obviously different. I didn't want to waste time with a fix for a problem when the problem wasn't fixable by my intended fix. Long story about what I finally did here that I don't have time to go into at the moment.

[kismet1]

Hi Pugsy - Thanks for your reply.

The 24 number is the time over red line % in the statistics. I am concerned because I can get an AHI number of 0.0 and yet get a message, "You had significant periods of major mask leakage", which makes me doubt the accuracy of the AHI number of 0.0. I am considering getting a full face mask to try to reduce the major mask leakage but don't know if I should be worrying about the leaks if my AHIs are consistently between 0.0 and 0.8. Usually my maximum leak rate is between 30 and 42 but I have had maximums over 100 a few times. For example on one night I had an AHI of 0.0 but I had leak rates that exceeded the redline for about 25 minutes where the leaks ranged from 24 to 45. For about 10 minutes the leaks ranged between 30 and 45. The rest of the night there were no leaks that exceeded the redline threshold. Any time the leak rate has gone over 50 it has been very, very, very, brief - as in seconds long. Once I have been approved as a registered user I will post some Sleep Head charts.

Thanks so much for your help.

n Sleepy Head that have gone as high as 24% while my AHI numbers have remained low.

First of all where are you getting the 24 number....is it the time over red line % in the statistics or is it the 95% number column in the statistics?

When you say "as high as" I am thinking that you are talking about the 95% number and not the threshold % number.
The 95% number isn't a % number it's a L/min number and if the worst it ever is happens to be 24 L/min then you DON'T have leak issues enough to impact the AHI.
First you have to understand the definition of a 95% number...it means at OR BELOW that number for 95% of the night. It is not an overall average and it is not where you spent 95% of the night. The "OR BELOW" part of the definition is very important.

In terms of accuracy of the data reported when faced with large leaks over 24 L/min....only the time over 24 L/min comes into question so even if someone had 15 minutes with a 40 L/min leak...only the small portion during the large leak is impacted and 15 minutes out of a 7 hour night isn't going to make much of a difference with the numbers of anything. It's too small of a piece of the night.

Resmed gives us the 24 L/min number...it's a very conservative number and things do go straight into the toilet at 1 or 2 or 3 or even more above that line. It goes in the toilet very gradually.
From my own past experience with varying degrees of leaks and a night where I had a nice progression from little to really big I have found that between 24 to 30 L/min leak doesn't really seem to impact things all that much. From 30 to 35 things start getting a bit iffy and I start seeing green unknown flags where previously there were OA or hyponea flags. The leaks are affecting the machine's ability to figure out what is going on...it knows something is going on but can't figure out what so it get a green unknown flag.
Over 35 L/min thing start getting more iffy....and maybe the machine is actually missing events and the further past 35 I went the worse it was..

Now do I sometimes hit 45 L/min leak...sure I do. It's never for very long...maybe 5 minutes but the data is only questionable for those 5 minutes. It doesn't make the entire night's worth of data questionable. Even if I had 1 apnea even a minute during those 5 minutes that the machine missed it wouldn't really affect my AHI all that much if they had been flagged.

Now if you are seeing the 24% time over red line statistic and not the 95% number...we need to have a different discussion and maybe look at how high it is going and probably look at some detailed reports. 24 % doesn't earn Mr Frowny but it's more large leak than I would want to see on a consistent basis. But before turning on panic mode need to see just how long it spent in large leak and how deep it went.

[kismet1]

Thanks for posting this - very similar to some of my data and charts.

Also my leaks seem to be intermittent - have major leaks during a period of an hour or so and then the leaks disappear for the rest of the night. Is this a sign of mouth breathing?

Could be mouth breathing but also could simply be mask movement. It's really pretty much impossible to tell one from the other on the detailed reports unless you have your mouth taped and you still get big leaks and since the tape has sealed the mouth the only thing left is mask movement.

Here's a good example of mask movement that could maybe be interpreted as mouth breathing because I use a nasal pillow mask.
The only thing is...these were with my mouth taped and the tape was secure in the AM...didn't come off.
These big leaks were all mask movement...new mask and trying different things and still getting large leaks so I wanted to make sure that the big leaks weren't mouth breathing because the fixes are obviously different. I didn't want to waste time with a fix for a problem when the problem wasn't fixable by my intended fix. Long story about what I finally did here that I don't have time to go into at the moment.

[Pugsy]

Really large leaks can cause the machine to miss some events....leaks over 35 L/min from my past experience when using a ResMed machine (different number for a Respironics user).
But it's only going to maybe affect the time when in really big large leak (like over 35...the time between 24 and 35 is probably fairly accurate data). Doesn't totally invalidate the entire night's worth of data.

I don't even give the large leak % a second glance until it reaches double digits and then I look to see how prolonged and how deep into large leak territory I went and if it is below 35...the second glance ends because the machine is fairly accurate up to that point.

Times above 35...well I look to see just how long I was up there way high. Half the night and I have a problem...10 minutes gets a shrug of the shoulders and I move on.

This is all assuming that the leaks don't wake me up and I am sleeping decent and feeling decent.
Any leak that wakes me up often needs to get fixed no matter how big or little it might be.

As far as going to a full face mask....if you want to try one that is fine but if you want to avoid one (and I am cool with that because I don't particular care for them either) and you consistently have big leaks flagged and they worry you...you have to figure out for sure if it's the mouth breathing doing it or the mask moving doing it. Going to a full face mask won't fix mask movement big leaks and could make them worse because there's more surface area to move.
Only way to know for sure is tape the mouth...doesn't mean you have to do it forever just one night to see if it stops the big leaks or not.
If it doesn't stop them and the tape didn't come off then you know those big leaks aren't mouth breathing leaks.
Now if it does stop them...then you get to evaluate more closely just how bad the leaks are and what do you want to do about them and do they really need anything to be done about them anyway.

My leak line is rarely pretty...probably some mouth breathing at times and for sure some mask movement at times but times deep in to large leak territory (above 35) are relatively rare and short lived. I sleep right through it all and I feel decent during the day so I don't see the need to go fixing a small problem with a mask that I simply don't like and there's no guarantee that mask would totally fix the small problem anyway.

Figure out for sure what the problem is and just how big is that problem...and the evaluate the options for fixing the problem once it identified. The report above...most people seeing it and not knowing that I taped my mouth would scream at me to get a full face mask and tell me I was losing all my therapy pressure out my mouth. To be honest even if it was all mouth breathing...I wouldn't go to a full face mask unless I saw this sort of report every night. A random really bad night doesn't get me to do anything. I ignore fluke nights. Chasing fluke nights will drive a person crazy.

If you are mouth breathing for sure and you don't want to go to a full face mask...try some of the other options to see if they might help resolve the issue or lessen the issue to something that is more within your comfort zone. There are other options available to try.

[palerider]

if you AHI is low and you have leaks then the machine adjusted for them
if it cant adjust then they will show up as AHs

This is simply wrong. At some point, the machine can't determine what's going on because the leaks are so bad, and therefore no events are flagged and the AHI is artificially low.

[JIMCHI]

I have been having periodic (2-3 times a week) major and prolonged mask leaks - like 20% of the night and with 90% leak rate showing around 40 and average leak rate of around 13. I am using a Resmed AirCurve 10 ASV. I monitor myself using both Sleepy Head and Resmed's MyAir. I was concerned about the leaks so I contacted my DME who contacted ResMed. They said to quit obsessing over the data and not to be concerned so long as MyAir shows the mask seal as "good".