It would sure be nice if we could all magically start using, and keep using, the term "FPAP" for fixed-pressure PAP, instead of using "CPAP" for that. Because in posts here I've seen a number of things like "Depending on your medical diagnosis, CPAP may not be right for you; APAP might be better." In that example, the intended meaning is obvious, given the context, but the use of "CPAP" is still wrong. In some other contexts, "CPAP" is even more ambiguous and confusing.
APAP is also one form of continuous positive airway pressure, so it's really auto-CPAP, but it's not constant or fixed pressure. But when the "A" isn't in the abbreviation, are we talking about constant pressure? In some cases yes, in other cases no, depending on the writer or speaker.
What can be done? I can and do suggest "FPAP", but what good will that do? I'm afeared that we're stuck with the ambiguity, just by accident. Does anyone here work for the ISO?