First, ER nurses work in the main entry point of a hospital or major health care facility while ICU nurses work on a separate floor that is generally far quieter and calmer than the bustling emergency room … The ICU is often the next step for patients who’ve made a (justified) trip to the emergency room after the ER team determines they’ve stabilized enough to move on. What is an ER Nurse? Head to toe assessment are done on … One major difference in this unit for nurses is the nurse to patient ratio—typically ICU units strive for one to two patients per nurse. The differences in working environment for an ICU vs an ER nurse. Just like ICU nurses, ER nurses need to be equipped with a quick critical thinking, decisive action PLUS a strong stomach. First remember in the ICU the enviroment is completely different and a more controlled kind of chaos. ER nurses are the first line of medical professionals you … I have been both....a ICU nurse and an ER nurse.