Delirium

Abstract

Delirium is a common, complex neuropsychiatric syndrome that occurs in approximately one in five hospitalized patients. It is associated with a range of adverse healthcare outcomes that are independently predicted by the severity and duration of delirium. Typically 50% or more of cases of delirium are missed, misdiagnosed, or diagnosed late in everyday practice. However, routine systematic cognitive testing aligned to formal screening for delirium in high-risk cases can improve detection in everyday practice. The relationship between delirium and dementia is complex; dementia is a potent risk factor for delirium and 50% of delirium occurs in the context of a pre-existing dementia, but evidence also indicates that the occurrence of delirium can accelerate the course of dementia and that many cases of delirium are followed by long-term cognitive impairment. Delirium is highly preventable, with a third of cases avoidable by addressing a variety of patient, illness, and treatment factors. Treatment of incident delirium requires careful consideration of underlying causes, aggravating environmental factors, and prudent use of pharmacological strategies, with antipsychotic agents the preferred pharmacological intervention. Careful attention to post-delirium care can minimize functional loss, address any psychological sequelae, and reduce the risk of further episodes.