Postoperative delirium is an acute disturbance of attention, consciousness, and cognition, often with hallucinations, disorganized thinking, and severe confusion, that occurs within a week after surgery. It is distressing for patients and families, challenging for staff, prolongs hospital stay and increases healthcare costs. It is associated with a faster long-term decline in cognitive function. The reported incidence ranges from 3 to 30%. Differences in assessment tools, assessor skills, and assessment frequency affect incidence estimates. The underlying vulnerability of the brain and the severity of surgical damage cause different rates in populations: older frail patients with minor procedures have rates of around 1-4%, younger patients with major surgeries around 20%, and hip fracture surgery up to 30%. This variability means that interventions to prevent delirium must show…