Is Respironics Leak Data Reliable???

I use a System One Auto set at 9 to 15 cm H2O and a Swift FX mask.

Recently I have had two nights when I KNOW I was leaking. The pressure changes on my APAP show it, but the leak data does not. I am concerned about this. My AHI's were also low, but now I'm not so sure that I can trust the data I'm getting from my machine.

Here's a night when I woke up enough to perceive that my nasal pillow was really leaky, but it was very late into the sleep cycle and I did not want to get up and fix it, other than unsuccessful attempts to reseat the pillows:


You can see that the pressure went up to the ceiling of 15 cm and stayed there, but my concern is that the green line indicating "normal mask fit" did not change, no "large leaks" were shown, and even the LPM stayed within the "acceptable vent rate" for this mask. The data shows very little as far as events, but I don't know if it's really trustworthy.

Here's a night when I woke up to find myself mouth breathing around 4 a.m.--I'm not sure for how long:


Again, the chart shows NOTHING as far as leak data. How can I trust this data???

I can't say for sure but on my end it seems reliable

I've only used the machine for two nights. The first night I used my opus mask without a chin strap and woke up in the early morning several times mouth breathing and noticed a larger leak rate in the data for those times. The second night I used a chin strap (The DME didn't give me one at first, I called after the first night and they got me one) and didn't wake up once with mouth breathing and had a fairly steady stream of even leak rate in the acceptable range.

Was the mouth breathing really bad? Maybe if it was minor that the leak didn't register as big enough. Maybe the air that usually leaves the vents just came out the mouth instead of the vents causing the leak rate to remain the same. This being if only a small mouth breathing instance occurred.

Again I'm no expert but that could be.

If you wanted to test it you could put the mask on, start up your machine and purposely mouth breath to see what the data shows under a controlled situation. Open your mouth just a little, then a little more until finally you have it fully open. You can see what the data does. Might see with just minor mouth breathing the leak rate stays the same because the air is just leaked out of the mouth instead of the vents as would normally happen but in a more extreme mouth breathing the leak rate rises.

I will try and get graphics up showing my leak rate data from the two nights that show the differences.