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+--- Thread: Better flowrate at lower pressure (/Thread-Better-flowrate-at-lower-pressure)
Better flowrate at lower pressure - Nsmon1313 - 05-15-2023
This might be a silly question, but has anyone else with an Apap noticed that when their pressure is lower, their flow rate looks so much better? It seems the higher my pressure goes the worse my flowrate is. I am wondering if the Apap is going too high and causing me to be worse. Is that possible? If anyone can provide any information I would appreciate it. I have severe fatigue and am watching my life just blow right by me. I just want help.
RE: Better flowrate at lower pressure - Sleeprider - 05-15-2023
Everyone seems to have a different therapy need, and pressure, EPR and even auto vs fixed pressure are all variables that work differently for individuals. No surprise to hear your preference for lower pressure, but without knowing more about your settings or seeing a chart it's hard to offer more than agreement.
RE: Better flowrate at lower pressure - Nsmon1313 - 05-15-2023
Thank you for taking the time to reply. I greatly appreciate it.
The first photo is a pressure range from 5-12. (I could not fit "snore" on the page.)
[attachment=50708]
The second photo is when I changed the pressure to 5-9. You can see in this picture that my flow rate seems to be better at a lower pressure. I also did not feel any better at this range. I think statistics were about the same as 5-12.
[attachment=50706]
I attached the snore to the 3rd picture since it would not fit on the first page, even after minimizing them vertically.
[attachment=50707]
I don't know if my flow rate looks good or not. I just know that I am still not feeling any better. Please let me know if there is anything I can add.
RE: Better flowrate at lower pressure - gainerfull - 05-15-2023
How are you evaluating your flow rate? What are you comparing specifically? Have you considered that when in REM sleep the flow rate will naturally look more choppy?
Also, you have some pretty big leaks to fix so perhaps the flow rate looks "better" considering your leak rate is lower at lower pressure range.
RE: Better flowrate at lower pressure - Nsmon1313 - 05-15-2023
Oh, I didn't realize the leak. Thank you for pointing that out. I also was watching some YouTube videos about this guy saying that the flow rate is supposed to look smooth, so that's why I thought the choppy stuff was bad. He said you need a smooth line instead of a line that goes up and down. Additionally, when its choppy and I zoom in, the respiration shapes always seem to be abnormal when comparing them to the chart on apneaboard. I attached a photo of a close up of the choppy stuff. They are not round like it shows they should be. That is about the extent of my knowledge on this stuff. I am trying to learn a little.
[attachment=50709]
RE: Better flowrate at lower pressure - Sleeprider - 05-16-2023
There is objectively no difference in the flow rates of the three examples your posted. The tidal volume and other respiratory statistics are identical and flow limit is almost unchanged. I think the flow limitation may be under-reported based on the close-up you provided and that is where you feel airway resistance. Usually, this would be most easily overcome with greater pressure support (difference between IPAP and EPAP), but that would only be available with a higher minimum pressure which you find less comfortable. EPR serves the same function as pressure support, and you are using a setting of 2. You do not get the full benefit of EPR until your pressure is 6.0 or higher because the minimum pressure of your machine is 4.0. So with a minimum pressure of 5, your delivered pressure is 5.0/4.0, and the EPAP pressure does not go above 4.0 until your pressure is in the 6.0 to 9.0 range.
My suggestion is to switch to fixed pressure to do some experiments with optimization. For example on the first night you could try fixed pressure with EPR 1 for a low pressure of 5.0/4.0. That could be followed with 6.0/4.0 by setting the pressure to 6 with EPR 2. Finally, try a pressure of 7.0 with EPR 3 for a 7.0/4.0 pressure. This sequence will let you evaluate the changes in pressure for comfort and efficacy without the complication of variable pressure.
RE: Better flowrate at lower pressure - Nsmon1313 - 05-16-2023
Thank you, for the suggestion. I will try this and see if it helps. I appreciate your explanation.