Sometimes people come into the ER who are all out crazy on drugs. The medical staff will wait for police to show up and handcuff him before they do anything, unless it's an emergency. My father told me of a time when he was a resident and a patient that started to freak out on drugs and became combative. Apparently the patient had his temporal artery slashed open with a box cutter in a bar fight. There wasn't time to wait for the police and the patient was bleeding out and attacking people so my father and several other residents ran at him, held him down, and sutured his ears to a bed so that he couldn't move or hurt anyone.