Delirium: acute cognitive dysfunction in the critically ill

PURPOSE OF REVIEW: The management of sepsis and the multiple organ dysfunction syndrome has traditionally been centered on dysfunction of organs other than the brain (e.g., heart, lungs, or kidneys), although the brain is one of the most prevalent organs involved. Recent studies indicate that nonpulmonary acute organ dysfunction may contribute significantly to mortality and other important clinical outcomes. Acute confusional states (delirium) occur in 10 to 60% of the older hospitalized population and in 60 to 80% of patients in the intensive care unit, yet go unrecognized by the managing physicians and nurses in 32 to 66% of cases. Delirium is an important independent prognostic determinant of hospital outcomes, including duration of mechanical ventilation, nursing home placement, functional decline, and death. Recently, new monitoring instruments have been validated for monitoring of delirium in noncommunicative patients receiving mechanical ventilation. Hence, critical care physicians and nurses should routinely assess their patients for delirium and develop strategies for its prevention and treatment. RECENT FINDINGS: This state-of-the-art review discusses in depth the delirium monitoring instruments, the pathophysiology and risk factors of delirium, its prognostic implications, and strategies (including ongoing clinical trials) to prevent and treat delirium. SUMMARY: Delirium is extremely common and has significant prognostic implications in critically ill patients. Routine monitoring and a multimodal approach to prevent or reduce the prevalence of delirium are of paramount importance.