Delirium in the Elderly

摘要

Delirium is an acute organic mentalsyndrome characterized by disturbancein level of consciousness, disorientation,attentional impairments, perceptual disturbances,cognitive impairments and occasionallysevere behavioral problems. Theterm “delirium” is based on the Latin rootsde, lira, and ium, which literally mean “agoing off the ploughed track, a madness.”The term delirium has been known since1 AD by the writer, Celsus, who describedit in De Medicina. Nursing staff will oftenuse the terms, “sundowning” or “ICUpsychosis” to describe the acute mentalstatus changes associated with delirium.Yet, neurologists prefer the term “encephalopathy”,which literally means “diseaseof the brain.” Regardless of the term used,delirium is not a benign condition andmarkedly extends hospital length of stayand increases the risk of further morbidityand mortality. The Diagnostic and StatisticalManual of Mental Disorders, 5th Edition(DSM-5) (due out in May 2013) willlikely define delirium as a disturbance inlevel of awareness or attention (rather thanconsciousness as in the previous edition),marked by the acute or subacute onset ofcognitive changes attributable to a generalmedical condition; and it tends to have afluctuating course. DSM-5 will also likelyadd supportive features and subtypes, suchas hypoactive, hyperactive, and mixed.1