Preventing postoperative delirium

Postoperative delirium is an acute disturbance in attention, awareness, and cognition, often involving hallucinations, disorganised thinking, and severe confusion that occurs in the week after surgery.¹ It is highly distressing for patients and families, is challenging for staff to manage, and prolongs hospital stay and increases healthcare costs. It is linked to faster long term cognitive decline,^{2 3} although the causal pathway remains uncertain. Reported incidence varies widely (3-30%).^{4 5 6} Variation in assessment tools, skill of assessor, and assessment frequency can influence estimates of incidence. However, underlying brain vulnerability and the severity of surgical insult can also produce strikingly different rates in different populations; for example, older patients with frailty undergoing minor procedures have low rates (~1-4%),78 whereas younger patients having major surgery have higher rates (~20%),⁹ and when both risks coincide (such as hip fracture surgery) rates can reach around 30%.10 This variability means that interventions to prevent delirium must show either a modest but reliable benefit within a specific surgical context or a clear and substantial benefit across multiple settings to justify widespread clinical adoption.