Drug misuse, intoxication and withdrawal Quiz: Ace Your Exams

A 40-year-old man is brought to the emergency department following a head-on motor vehicle collision. Trauma workup demonstrates a fracture of the right femur and tibia for which the patient is admitted and scheduled for surgical repair the next day. Twelve hours after admission, the patient becomes agitated, hypervigilant, and paranoid. He repeatedly tells the nurse that he hears voices calling out his name and someone is planning to kill him. He frequently attempts to remove his morphine PCA pump. Past medical history is significant for alcohol use disorder, opioid use disorder, and moderate marijuana use. Temperature is 37.5°C (99.5°F), a pulse is 88/min, respirations are 17/min, and blood pressure is 135/87 mmHg. Physical examination shows an alert and oriented male with tremulousness and diaphoresis. Which of the following is the most likely etiology of this patient’s condition?