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large Leaks and AHI...correlation? - Allessio77 - 12-03-2017

I just had my 5th night sleeping with my APAP and had my best AHI reading (.8). The other four nights were in the 3's and 4's.

But, I also had the largest leak on my Sleepyhead report:
      Ave Leak Rate           3.66
      90% Leak Rate        15.60
      % of time > leak rate threshold  3.40%

Can anyone interpret this data for me?
Is there a relationship between AHI and High Leak rate?  ( I don't recall my mask coming off.)


RE: large Leaks and AHI...correlation? - Sleepster - 12-03-2017

Hard to infer anything like that from one night's data. Plus, being above the leak threshold means the machine can no longer measure AHI reliably.

There is no clinically significant difference between an AHI of 3 or 4 and and an AHI that's less than 1.

Your main concern, in my opinion, is figuring out how to avoid the high leak rates that you had that one night. It could be that your mask got dislodged against your pillow, or something like that. Not an issue, as long as it doesn't keep happening. The fix could be something as simple as tightening the straps.


RE: large Leaks and AHI...correlation? - Walla Walla - 12-03-2017

I tend to disagree. I think a leak rate of 3% over the red line is not a big problem. Now if it was around 10% or more I'd agree.

Also for some the difference between 1 and 3 AHI can be a big deal as far as quality of sleep.


RE: large Leaks and AHI...correlation? - Allessio77 - 12-04-2017

How about those three sleephead statistics:

Ave Leak rate
90% Leak rate
% of time above Leak rate Threshold

What do they mean? What importance does each of them have? When are they important? At what levels are they important?

Thanks


RE: large Leaks and AHI...correlation? - Walla Walla - 12-04-2017

Here's a link to Beginners Guide to SleepyHead. There's a section on leaks in it. It should explain it all.

http://www.apneaboard.com/wiki/index.php?title=Beginner%27s_Guide_to_SleepyHead


RE: large Leaks and AHI...correlation? - Allessio77 - 12-04-2017

Walla...read the section...but hard for me to actually understand. Here is a graph of the LL situation:


<blockquote class="imgur-embed-pub" lang="en" data-id="a/TA20J"><a href="//imgur.com/TA20J"></a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>



https://imgur.com/v8PM6Jo

Ave Leak Rate           3.66
      90% Leak Rate        15.60
      % of time > leak rate threshold  3.40%


RE: large Leaks and AHI...correlation? - Walla Walla - 12-04-2017

The chart I'm looking at is showing 13 almost 14 percent over the red line which is large leaks. Yes that is too much leaking going on.


RE: large Leaks and AHI...correlation? - Sleepster - 12-04-2017

(12-04-2017, 03:16 PM)Allessio77 Wrote: Ave Leak Rate           3.66
      90% Leak Rate        15.60
      % of time > leak rate threshold  3.40%

The leak rate threshold for a ResMed is 24 L/min. Meaning that anything above that is considered "too large".

Your average leak rate of 3.66 is well below 24.
Your 90th percentile leak rate is 15.60, meaning that 90% of the time your leak rate is at 15.60 or lower.
But 3.40% of the time you are above the leak rate threshold of 3.40%

If this occurs regularly it needs attention. That could be something as simple as tightening the mask straps, or using a different pillow.


RE: large Leaks and AHI...correlation? - Allessio77 - 12-04-2017

(12-04-2017, 04:27 PM)Sleepster Wrote:
(12-04-2017, 03:16 PM)Allessio77 Wrote: Ave Leak Rate           3.66
      90% Leak Rate        15.60
      % of time > leak rate threshold  3.40%

The leak rate threshold for a ResMed is 24 L/min. Meaning that anything above that is considered "too large".

Your average leak rate of 3.66 is well below 24.
Your 90th percentile leak rate is 15.60, meaning that 90% of the time your leak rate is at 15.60 or lower.
But 3.40% of the time you are above the leak rate threshold of 3.40%

If this occurs regularly it needs attention. That could be something as simple as tightening the mask straps, or using a different pillow.

thanks...this was my worst result in 5 nights. I am thinking it might have to to with mouth breathing because I caught myself unable to hold back the air many times that night. (I had tried a chin strap a couple of days ago, but had to remove it in an hour due to discomfort). Is that possible?

It the instructions for sleepyhead, it was the ResMed material that confused me. The data seems to mean something different for ResMed users than for others.

I have a mouth guard coming to see if that helps, and I also have a full face mask coming tomorrow that I asked for when I get a cold or flu.


RE: large Leaks and AHI...correlation? - Sleepster - 12-04-2017

(12-04-2017, 05:02 PM)Allessio77 Wrote: I am thinking it might have to to with mouth breathing because I caught myself unable to hold back the air many times that night. (I had tried a chin strap a couple of days ago, but had to remove it in an hour due to discomfort). Is that possible?

Actually, it's the most likely explanation. Look at your leak rate graph and see if it moves up and down a lot. When it's high you're mouth-leaking.

The chin strap should be loose enough that it allows you to still open your mouth when you try, but tight enough that your mouth doesn't just fall open when you're asleep.

Quote:I have a mouth guard coming to see if that helps, and I also have a full face mask coming tomorrow that I asked for when I get a cold or flu.

The full face mask is your best bet to avoid mouth leaking. The inside of your mouth will be pressurized the same as your airway, and that stops the leaks since there is no pressure difference between the mouth and the airway.