Delirium, the clinical expression of encephalopathy, is important in the context of COVID-19, because (a) delirium may be a symptom at presentation and/or during management, and (b) the behavioural changes commonly seen in delirium, particularly agitation, may make management including delivery of care and reducing the risk of cross-infection more challenging.
Older people are at the greatest risk from COVID-19. If infected they may present with or develop a delirium. However, delirium is not exclusive to older people and may well be seen in any patient with severe infection, adult respiratory distress syndrome, and those requiring invasive ventilation on ICU units.