Hi Steve, welcome to the MHF family!
I know what you mean about being rusty... I feel much more confident about the areas of math that I frequently use on a daily basis, and it's the areas that I don't have to use that I look at and think oooh yeah, I remember that. I still laugh when I think of my 2nd grade math teacher who would always start out each class by saying "Math is FUN-damental" lol
What area of medicine are you working in now? I'm assuming you're in medicine since you mentioned the anesthesia program you're going to.