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I had similar problems as you and Pugsy got me through them in a similar fashion raising the minimum a bit and keeping the upper pressure at max (20) until the right range was found. Over time I got used to it and even managed to adjust it down a bit.

She is the pro far more than I, but as she will tell you some of us have problems with flow limits for a variety of reasons that the Autoset can only handle with more pressure. I switched to a Vauto which allows more pressure support (like EPR but instead of subtracting pressure for inhale it adds pressure for exhale and is called PS for pressure support). Once I switched to the Vauto with a PS of 4 the flow limits are almost zero and my pressure is much lower as a result.

Give yourself time to see how the new pressures work. You may end up being a candidate for a Vauto and could pick one up used then sell the Autoset.

Jlfinkels wrote: ↑

Mon Apr 04, 2022 11:14 am

Flow limits are an impairment to the flow-rate through the respiratory tract. Nasal congestion is a typical contributor. Flow limits can occur both on inspiration and expiration.

Your flow limits are driving up your pressure. Look closely at the flow limit graph and then look at the pressure graph, you will see how the pressure increases when the flow limits increase. You may want to consider increasing your pressure from 10-15 to 12-20 as a way to test where the real max pressure needs to be and also to see how it affects your flow limits.

Thanks for the input
I adjusted the pressure range upwards to 12cmH2O-20cmH2O.
At 1st look, It seems to be working, because the AHI’s now stay consistently low, close to a median of 0.60 over a week and the( red ) pressure line on the graph is comfortably lower than the max set value of 20cm H2O.
I thought that it was because by raising the max pressure value to 20cmH2O, the machine allows more pressure to open the airway when it detects a constriction, hence it forestalls OA’s and H’s .

On a closer look, however, I didn’t see a correlation, as I expected, between the red line value on the pressure graph ( I suppose the inspiration pressure?) and the pressure registered by the machine at the time of an H or OA event.
In fact, sometimes H’s and OA’s events occur with a red line pressure significantly lower than the maximum setting of 20cmH2O. For inst, on the screenshot of April 11 all the OA’s occur when the red line on the pressure graph is as low as 11,93 cmH2O, a far cry from the 20cmH2O of the new 12cmH2O-20cmH2O setting.

Why for some ( probably most) OA’s and H’s it takes a pressure close to the upper limit of the setting, while in some other cases it doesn’t need to be so high?
May be I am missing something, Quite possible!Can anybody comment?

Thanks

Ittiandro

ittiandro wrote: ↑

Wed Apr 13, 2022 11:12 am

Why for some ( probably most) OA’s and H’s it takes a pressure close to the upper limit of the setting, while in some other cases it doesn’t need to be so high?

Because we don't sleep the same at all times during the night.
We often change position as well as go through all the various sleep cycles.

You probably already know that often for a lot of people the OSA worsens when we are on our backs and thus might need more pressure. Also it is common for REM stage sleep to cause a worsening of the OSA and need more pressure.

Pugsy wrote: ↑

Wed Apr 13, 2022 11:34 am

ittiandro wrote: ↑

Wed Apr 13, 2022 11:12 am

Why for some ( probably most) OA’s and H’s it takes a pressure close to the upper limit of the setting, while in some other cases it doesn’t need to be so high?

Because we don't sleep the same at all times during the night.
We often change position as well as go through all the various sleep cycles.

You probably already know that often for a lot of people the OSA worsens when we are on our backs and thus might need more pressure. Also it is common for REM stage sleep to cause a worsening of the OSA and need more pressure.

It makes sense.
Do you think that the new higher pressure setting ( 12cmH2O-20cmH2O) might have stopped in their tracks potential OA's and H's ?

Thanks

Ittiandro