How to make decisions in the emergency department

First, when you walk into a room, mentally say to yourself, “is this patient going to die right in front of me?” If the answer is “yes,” then go into ABC/ACLS/ATLS/PALS(EPLS) mode.
If the answer above is “no,” then ask yourself, “is this patient sick enough to be admitted, or well enough to go home?”
If the patient is going to be discharged, then figure out what the worst possible conditions that could harm/kill the patient based on the patient’s chief complaint, and come up with a way to systematically cross them off the list so you can feel warm and fuzzy about discharging them home.
If they are going to be admitted, then figure out what tests to order so you can initiate lifesaving treatment.