What are the age requirements?

BY "CRNA" do you mean certified registered nurse anesthetist? Of course do further research as I am no expert, but I do not believe that they can discriminate age for employment if you are over 18. The educational programs may be different. They can write the qualifications to apply to the program that you have X number yrs of experience as an ICU nurse, which will raise your age at the time that you qualify by a few years. Some hospitals require that you are over the age of 18 to work in certain positions, but I would be rather impressed that if you were a nurse anesthetist before 18.