[Diagnosis and management of delirium in older adults].

Delirium, also known as acute confusional state, is an acute brain disorder characterized by cognitive disturbances, particularly attentional deficits, potential behavioral changes, and altered vigilance, with a sudden onset and fluctuating course. It is a common condition among hospitalized older patients and has serious consequences for the patient, their family, and the healthcare system. It is considered an "acute brain failure" that often occurs in the context of underlying cognitive and cerebral vulnerability, similar to how acute kidney injury complicates chronic kidney disease or how acute heart failure exacerbates chronic heart failure - usually in the presence of a precipitating medical factor, often infectious, metabolic, perioperative, or neurological. This narrative review aims to describe the symptoms that allow the diagnosis of delirium in older adults, the available diagnostic or screening tools, as well as the complex and bidirectional relationships between delirium and dementia. The management of delirium, including non-pharmacological measures, will be discussed, along with symptomatic pharmacological treatments, which should be reserved for severe cases despite their low level of evidence.