I understand completely your fears. I work on the M/S/P unit until ICU is short staffed. I get pulled because I have ACLS and PALS (since when does this alone make you an ICU nurse). Luckily most of the nurses I work with in ICU realize this and I get the "light" patients. I ask continuous questions, most are terrific teachers and I have learned a lot. But I was told that you should have at least a year experience in ICU before being considered an ICU nurse. I have a long way to go but the knowledge I've gained so far is priceless. Good luck to ya!