To do triage in the ED most of the time "the rule" is at least 1 year experience in the ED, ACLS and PALS certification.
ED vs Trauma Nurse. My personal experience is that in smaller ED, rural ED, etc you, as a nurse do a lot more, practice skills during trauma encounter until pts stabilized and transferred to higher level facility. TNCC and ENPC is desirable but not sure if always required right away. Larger, teaching hospitals do have a trauma nurse and trauma teams. As a nurse there you really do not do as much except drawing blood, manual BP, assist CPR if needed, operate rapid blood transfuser, transport pt to CT and giving pain, nausea meds when ordered. Evidence-based practice reading and certification in Trauma nursing is a good thing but some trauma nurses are not even trained in obtaining US guided IV's or inserting EJ lines and they do not have to do the assessment. Trauma team shouts everything and the CN does the charting. Very important part is the charting and the exact time of Trauma team arrival. When stabilized the pts are transported out of the trauma bay: either another part of the ED, OR or admitted to a room.