The bottom line is CRNAs can be and are independent in many venues, AAs CAN NEVER be independent, so you are worrying about a comparison of "apples to oranges". It's nice that you are happy you can always have an MDA to fall back on--Independent CRNAs rely on themselves and their surgical colleagues if necessary. As for safety issues, there can be no general studies comparing AA and CRNA performance, since AA's only practice in a team environment--any comparison would have to be in the environment where MDAs claim they have control over everything. And, I am sure, many AAs are about as capable as CRNAs who only practice in the team environment. Water seeks its own level. Regards, Lou