Is mouth leak tricking my AHI ?

[Djabag]

Hi
I've been using my CPAP for about 2 months and i get a AHI between 1-2 and feel happy about that.
But could a mouth leak trick my AHI results ? I read somewhere that if you have many flat tops in the Leak rate diagram i could mean just that.
I use a Dreamwear nasal mask.

Regards

/per

[DeepBreathing]

Your machine can accommodate a leak up to 24 L/min. If your leak is over 24 the machine can't generate sufficient airflow and can't effectively diagnose or treat your apneas and hypopneas. So the question is: How bad is the leak, and for how long does it occur?

[PaulaO2]

Yes, the flat topped leak typically means mouth leaks. During a large leak, the machine cannot keep up and the "echos" from the air pulses are not read correctly. It can report either a too high (reads false ones) or too low (cannot detect events).

[Stom]

As PaulaO2 noted, when their are large leaks, the APAP can't tell if you are having central or obstructive apneas. An APAP does not treat central apneas, so if it can't tell one from another it can't tell if it should up your pressure in response to an event, so it doesn't and you don't get the adjustment to treatment pressure you need.

[Sleepster]

I read somewhere that if you have many flat tops in the Leak rate diagram i could mean just that.

It's worth investigating. Can you post leak rate graph for us to look at?

[Djabag]

Hi
Hope you can make something out of this. Please let me know if you need any more screenshot..

Regards
/per

[Sleeprider]

Whatever you did worked. There are no significant leaks in the most recent data. Looks great!

[Sleepster]

All the numbers look good, and to answer your original question, leak rates that low won't affect the AHI. The manufacturer claims it can reliably measure AHI up to a leak rate of 24 L/min. Yours are down around 10 L/min, so you're more than good.

However ...

The leaks that you do have could be causing you to wake up. You see those periods of time where the leak rate is at around 10 L/min for several minutes, then it suddenly drops to near zero? That could be you, awoken by the air hissing out of your mouth, followed by you falling back asleep again after you close your mouth back up. These awakenings might be so subtle that you have no memory of them, but they could ruin your night's sleep and make you more tired than you otherwise might be. Compared to not using a CPAP machine, this is a big improvement in reducing the number of awakenings, but it may not be as good as it can get.

If this is something that's a concern for you, try a chin strap, or better yet a full face mask. My situation was similar to yours, I dreaded the idea of a full face mask, but eventually I tried it found out it's not so bad. But best of all I finally started to feel rested during the day, and after a while my fragmented sleep finally faded away.

[Djabag]

Stilll have some thoughts about the mouth leak could effect my AHI. The last months my AHI gone down from around 2 to under 1.

If you look at my screenshot do it indicate any mouth leak? I still have some problems with being a bit sleepy during late afternoon.

Kind regards
/per


Kind regards

[Walla Walla]

You have a couple of places where it looks like mouth leaks. However the leaks are within the the machines limits for detecting events. I don't think they have any effect on your AHI on this chart.