ECM5 you asked " Why does turning EPR off help?"
Why? because it increased your EPAP and the EPAP is the main thing the CPAP uses to splint your airways.
Rule #1 with the ResMed AutoSet: when you increase the EPR you need to increase the pressure by the same amount to keep the EPAP the same.
Conversely:
Rule #2 with the ResMed Autoset: when you lower the EPR you need to reduce the pressure by the same amount to keep the EPAP the same.
Kind of back to front ResMed logic to keep you confused and returning to the DME for "advice".
So what you did was lower/remove the EPR and in so doing you increased the EPAP hence you had less OSA.
From this chart you posted earlier you can see your EPAP (which is the Pressure minus the EPR) is too low. You set the EPAP at 6 cms (7 cmw minus EPR of 1 = 6 cmw). This is less than ideal to control your OSA. You can see that every time the EPAP falls you had some OSA and the machine responded accordingly.
[attachment=43031]
You can easily figure out a better starting EPAP for yourself: zoom into the OSA event and record each EPAP at which each OSA commenced, write this down/spreadsheet this and work out the average.
Or simply look at where the machine is keeping your EPAP for most of the night. On the chart you posted earlier: your Med EPAP was 7.2 and your 95 EPAP was 8.72, so, if you like, you should aim to keep your EPAP closer to the 7 or 8 cmw mark.
You could also consider the For Her mode:
The For Her "resets" the min EPAP after the 2nd OSA to prevent the EPAP falling too low for the rest of the night.
Good read here:
For Her McArdle
An extract from the article in case you don't have the time to read the whole thing:
(Quote: )
Another novel feature of the AfH algorithm is a
moving minimum AutoSet pressure (i.e., a minimum pressure is set to which pressure decreases during sleep periods devoid of respiratory events). If apneas occur within a short time period
the minimum AfH pressure will automatically increase and the pressure will not decline below this level for the remainder of the night’s therapy. The purpose of this is to minimize inappropriate pressure decreases during REM sleep that could occur with the standard AutoSet algorithm. It is possible, for example, that the standard AutoSet algorithm pressure could decay below the critical closing airway pressure during REM sleep, which can result in several apneas at the beginning of REM sleep until the device responds with appropriate pressure increases. This could be particularly important in women, who have been shown to have a predominance of REM-related OSA compared to men. During REM sleep CPAP pressures may need to be higher to maintain patency of the upper airway secondary to a REM-related reduction in the tone of upper airway muscles. It is also possible that this algorithm feature could reduce pressure variability, contribute to longer REM sleep, and reduce REM-related respiratory events.
(End Quote: )
Lots to digest I know, but hope this helps a little.