One of the principal distinctions between postoperative (Post-Op) delirium and postoperative cognitive dysfunction (POCD) is the time frame in which they are found. Emergence delirium occurs in the operating room (OR) or immediately after in the post–anesthesia care unit (PACU). Postoperative delirium occurs 24 to 72 h after surgery. POCD is measured at weeks to months after surgery and anesthesia. Pre-Op, preoperative. Reproduced with permission from Silverstein et al.⁹⁹