Ultimately, I found the "secret" to finding the sweet spot settings was reducing pressure to the lowest that would control obstructive events, while remaining low enough to prevent creation of central apnea events. Maintaining a low expiration pressure was also critical, as was the humidifier setting, believe it or don't. My average weekly and monthly AHI continued to swing up as high as 22 until I adjusted my BiFlex setting to "3" and System One resistance to "X1." These are not adjustments that are typically recommended or highly documented, but they were the icing on the cake for me to reduce and mostly eliminate "periodic breathing" episodes, and to keep my daily AHI below 5.
I take opioid pain meds every five hours, with a large dose of time release medication at bedtime, along with a single daily 1mg dose of clonazepam at bedtime, These present a confound for successful CPAP/BiPAP. Yet I have finally found success by systematically and slowly attending to some unlikely adjustments buried deeply in my machine. I've learned that settings, even for Auto BiLevel "BiPAP," are specific to each individual. What works for one person may not be the answer for you or me.
I'd like to make a suggestion to improve clarity in the Profile section, where we list our machine settings. I think it would be useful to have individual fields for every setting on each brand and model of CPAP machine, rather than the limited free-text fields currently in use. Such a feature could furnish more extensive information about each person's settings (if they choose to fill them in), and might help new users arrive at settings that work for them. For my Philips Respironics System One machine, these would be the fields I would want to see, and into which I would enter my current settings (seen in parenthesis here):
Mode (Auto BiLevel)
Min/Max Pressure (7/12)
Biflex setting (3)
System One resistance (X1)
Again, just a suggestion for an already sophisticated and extremely helpful board, that has clearly been a huge help to me and to users all over the globe. Thank you!