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Help to optimize Flow Rate
Help to optimize Flow Rate
Hi All:

I am now 6 months on APAP and doing well, thanks to help from this amazing community.

I am interested in my Flow Rates on the 28th August.


Most of the night reflects the normal shape of my breathing in the Flow Rate: Pretty spikey, flat top, downsloping, (type 4 I think it is called).
But then, for nearly 2 hours, (and just once in 6 months) I get this beautiful smooth breathing pattern between 23:30 and 00:15. See orange/brown vs blue/grey (my normal breathing pattern).

I know I am asleep at that time: note the Flow Limitations increase, which pushes up the EPAP and IPAP pressures. Steady pulse rate, steady O2, very little mouth leaking. Pressure of 10.4 o 10.6 EPAP 9.4 to 9.6
But then as the Flow Limitations reduce (due to APAP or positional change?) and the leaks increase, the Flow Rate becomes all spikey again.

Why is the Flow Rate so smooth when the Flow Limit chart shows Flow Limitations rather higher than the rest of the night?
Surely the smooth pattern is better?
Am I correct in thinking the smoother pattern is what I should be aiming for all the time?
How shall I duplicate this?
Should I be on higher pressures most nights?
(I tend to avoid higher pressures due to side effects)

Very interested in anyones' thoughts here..
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RE: Help to optimize Flow Rate
Talking to myself here, but here goes...

No replies yet, but while I wait for these I am still speculating about this.

My question is why is my flow Rate so smooth in the orange section in the attachment in post #1?

If I can understand that, I can try and reproduce that with appropriate machine settings.

My normal irregular/sloping Flow Rate indicates flow limitations, and as per recommendations in response by Bonjour to my other posts I have increased my EPR to 3, the highest I can go with my Resmed Airsense 10 Autoset.

In the orange section from 23:30 to 00:15 I read the chart as follows:

1. Flow Limitation goes up for some reason.
2. Resmed responds and increases the Pressure to 10.6 and EPAP to 9.6
3. Resulting in a nice smooth flow rate at these Pressures.

I can think of only 3 reasons this happened.

1. Random event. Hence no way I can duplicate that flow rate curve, end of story. Or

2. I could I have been side sleeping as a cause for better Flow Rate curve? I doubt that because the Flow Limitation should theoretically be less sleeping on my side than when sleeping supine. Or

3. Supine sleeping with a specific phase of sleep that caused increased FL to which the machine responded.

In which case it seems I need EPAP to be at least around 9.6 range all night long.

What interests me is that during this period of higher pressures and smooth Flow Rate, the mouth and mask leaks were practically nil. How is this possible?
Perhaps something else is going on here.

Is this the tongue sucking technique starting to work?
Perhaps by the tongue and soft palate being stuck together, surface tension maybe?
Thus, blocking xPAP pressures from getting from the nasopharynx to the mouth? If so, the higher pressures would only go from nasal mask to airways to lungs and back out again, with no flow into the oral cavity to cause mouth leaks. If that is the case, this is something I will pursue. I have been trying this during the day over the last few weeks and on falling asleep.

Any other thoughts suggestions would be welcome.
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RE: Help to optimize Flow Rate
Looks to me like the "smooth" flow rate section in orange matches up perfectly with a period of almost zero mask leakage (Leak Rate).
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RE: Help to optimize Flow Rate
That's what it's (mainly) all about: leakage. The second flow rate shows some flat course around the zero line, indicating a (mouth) leak, clearly at 00:44:30.
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