Which factors are associated with higher risk of postoperative delirium?

• A. Female Gender.
• B. Age, Preexisting Cognitive Impairment, Polypharmacy, Infection, Dehydration.
• C. Exercise.
• D. None of the Above.

Answer: (B)

Postoperative delirium risk climbs when several factors that lower brain reserve and increase CNS vulnerability are present. The option that lists age, preexisting cognitive impairment, polypharmacy, infection, and dehydration includes several of the most well-established contributors. Older age means less neuronal reserve to cope with anesthesia, surgical stress, and metabolic changes. Preexisting cognitive impairment indicates existing brain dysfunction, which makes delirium more likely when stressed. Polypharmacy adds the risk through higher anticholinergic load and potential drug interactions that disrupt neurotransmission. Infection triggers systemic inflammation that can affect brain function and neurotransmitter balance. Dehydration leads to reduced cerebral perfusion and electrolyte disturbances, both of which can precipitate delirium.

Other choices don’t fit as well because female gender is not consistently identified as an independent risk factor for delirium, and exercise is generally protective rather than a risk factor. “None of the above” would be incorrect since these factors are truly associated with higher risk.

In clinical practice, recognizing these risks preoperatively helps guide prevention: optimize hydration, review medications to reduce anticholinergic burden, treat infections promptly, and implement delirium-prevention strategies such as early mobilization, cognitive orientation, sleep hygiene, and careful pain management.