Hi allibear! You are just starting in your career but if you really want to be a CRNA bad enough you will succed, no matter what anyone may tell you. Yes, grades do matter but that's not all that schools look at. Get the best grades in school that you can. Learn all you can about critical care in your nursing program, get into a critical care internship when you graduate, get your certification as soon as you can, and then apply to as many schools as you can. But most of all, if at first you don't succeed, keep trying!!