Pressure needs (like over 20 cm).
Or simply comfort issues at any pressure. Bilevel allows for a greater difference between inhale and exhale and it's that difference that offers us the greater comfort.
Or in the case of those specialty bilevel machines for special problems...a special problem like centrals.
Some bilevel machines are nothing more than a cpap/apap machine with greater ability to make that difference between inhale and exhale bigger than what a person can get with using whatever exhale relief their cpap/apap has available.
Some bilevels are very complicated with a lot more than just exhale relief being offered.
Wow, it sounds very complicated.
In my opinion with what I've read here in this forum and issues that I'm struggling with I feel that I might need Auto Bipap? But of course I know that my doctor has to decide this.
I just don't know if the problems that I'm having are enough to convince my doctor that I might need BIPAP.
I see my doctor next month and I do want to ask her If she will order another sleep study for me and see what happens after that.