Final answer:
A 72-year-old patient showing acute agitation and confusion post-surgery is most likely experiencing delirium, potentially induced by medications such as hydromorphone or alprazolam.
Step-by-step explanation:
When a 72-year-old patient shows signs of agitation and confusion two days after surgery, and these symptoms fluctuate throughout the day, we can suspect he might be experiencing delirium. This condition is characterized by sudden changes in attention and cognition, often precipitated by medical illness, surgery, or medication changes. Given the patient's medication list, it is important to consider the role of hydromorphone (Dilaudid), a potent opioid, and alprazolam (Xanax), a benzodiazepine, both of which can contribute to delirium, particularly in the elderly due to their sedative and cognitive-impairing effects.