Flow rate kink at end of exhalation

[ahuman]

I sometimes have a kink at the end of the exhalation - more of a small dip than a flattening. Occasionally, it can even go slightly above zero and then back below before the full inhale. Is this an air supply issue? What should I experiment with? Could this mean EPAP is bottoming out too low or is it not low enough to let me smoothly finish the exhale? The upward curve of the exhale could be smoother in general if that matters.

[BigWing]

I think at least ONE flow rate graph would help.

[ahuman]

Here's one screenshot: https://lh3.googleusercontent.com/drive-...v=s1600-v0

[Sleeprider]

It looks like spontaneous inspiration is beginning and the IPAP pressure support is not keeping up. Increase trigger sensitivity to high and let us know if that solves the problem.

[ahuman]

IPAP is not responding fast enough? Is there a way to be sure that is the issue?

I'm already at high trigger sensitivity. Should I try very high?

[Sleeprider]

Changing trigger sensitivity is simply a trial and error to see if it makes a difference. Was the "kink" there before you changed to high trigger? I should have checked the chart for settings because it's right there. Anyway, I don't know whether trigger will make any difference, but this is the only way I know to find out. Are you even aware of a physical sensation from this, or just looking to make the chart perfect?

[ahuman]

It's present on a day with medium trigger that I happened to check. I'll try very high to see if that helps. I had rolled back to medium because I didn't want the machine to reduce my exhale, but perhaps that was the wrong direction.

These curves can't be perfect, but possibly improved. I noticed this and wondered if it was connected to the sucking in the mask sensation. Possibly that occurs when this kink is above the zero line. There's no real way to know as I'm not able to track exactly when that occurs. 

Do others not have this pattern?

[Sleeprider]

The flow sensor is in the device between the fan and humidifier. There is a lot of potential for interference. To be honest, I don't often examine the flow rate for these kinds of anomalies, even for myself. My nightly flow chart is full of just awful looking stuff that I don't notice on a sensory level, so I don't chase it.

[ahuman]

Very high trigger seems to be worse. The kinks are worse with more clearly going back down before up. The curve shapes seem more jittery too. Should I try low trigger instead to compare? Adjust pressure somehow?

[Sleeprider]

I would move back to medium trigger, or try low. As I said before, this a a trial and error experiment to find the best and most comfortable result. It seems like you did okay at medium trigger.