Delirium in the Critically Ill Patient

Delirium, a disorder characterized by altered consciousness, inattention, and global disturbance in cognition, is a common syndrome in the intensive care unit (ICU), affecting up to 90% of critically ill patients. Over the past 20 years, ICU delirium has gained substantial attention as a major health problem, due to its high prevalence and association with adverse patient outcomes including prolonged length of stay, long-term cognitive, physical, and mental health impairments, and early death. The pathophysiology of delirium is complex and poorly understood, with a number of potential mechanisms and pathways. Prevention and early identification of delirium, using multicomponent strategies and validated bedside tools, respectively, are vital for management efforts. Clinical practice guidelines for delirium prevention and treatment recommend the emphasis on routine screening for delirium, protocol-driven assessment and management of analgesia and sedation, sleep promotion, minimization of provoking factors, and the importance of early rehabilitation and mobility. As the topic of ICU delirium is extensive, this chapter will focus specifically on (1) pathophysiology; (2) presentation; and (3) prevention and management strategies of delirium.