Delirium

Delirium is an acute cognitive disorder involving sudden disruption in attention and consciousness with cognitive and behavioural symptoms. Delirium affects roughly 23% of general hospital populations and 32% of older inpatients, rising to 48.9% when dementia is also present. The hypoactive subtype of delirium was the most common subtype observed in the RESTORE trial, accounting for two of three cases. ICU delirium rates typically range from 28.6% to 31% but can reach as high as 83.3% in specific critical care environments. Delirium occurs as a physiological consequence of an underlying medical condition and has a variable course. Delirium is associated with prolonged hospital stays, higher healthcare costs, cognitive and functional decline, and increased mortality. A substantial minority of patients still meet delirium criteria six months after an episode. Delirium is associated with three to four times higher in-hospital and long-term mortality, longer hospital stays, and a broad range of adverse outcomes. Delirium increases long-term risk of dementia, institutionalisation, and caregiver burnout.