Nocturnist

A physician, usually one of the best in his or her feild, who is so adept at practicing medicine that they frequently handle any and all after hour emergencies in large hospitals with little to no help at bedside from colleagues or subspecialists. Usually high income earners with strong work ethic, very often referred to as the Guardian Angels of the hospital due to their ability to single handedly solve problems and keep critically ill patients alive at night. Can often teach Advanced Cardiac Life Support (ACLS) in their sleep. Often exclusively work at night. Proper noun, capitalization important differentiator from non-physician references.