17 - Delirium

Abstract

The delirium syndrome is defined by a change in consciousness, with a reduced ability to focus, sustain, or shift attention that occurs over a short period of time and tends to fluctuate over the course of the day. Delirium can be caused by a wide variety of medical illnesses, medication side effects, and intoxications or withdrawal from substances. Delirium is common in older adults in all clinical settings. Delirium is associated with increased mortality, poorer functional status, limited rehabilitation, increased hospital-acquired complications, prolonged length of hospital stay, increased risk of institutionalization, and higher healthcare expenditures. The clinician’s primary objective should be the prevention of delirium because once delirium symptoms have developed, the older patient is at risk for poor clinical outcomes. Contributing factors of delirium are categorized into two groups: first, the cluster of predisposing or vulnerability factors, and second, the cluster of precipitating or trigger factors. Delirium is diagnosed if a patient has an acute change in mental status with inattention, accompanied by disorganized thinking or a change in alertness. A thorough history, physical examination, chart review, and laboratory testing should be completed to identify reversible causes of delirium. Successful management of delirium depends on the accurate delivery of two types of interactive therapies: (1) treatment of the underlying causes, and (2) supportive care that targets the two types of delirium: hyperactive (agitation) and hypoactive (lethargy).