I was an ICU nurse for 15 years before going to hospice and then to teaching. When I had to bring my clinical group through an ICU rotation I was scared to death as it had been 7 years since I had been in one, but it took me about 2 hours to become comfortable again, it's amazing what comes rushing back when you are back in the atmosphere. My biggest challenge was the different equipment but, that didn't take long either. ICU nursing is a way of thinking, critical thinking, and once you learn it, you never actually stop using it in your practice. Good Luck to you, I think you will be fine :)