Acute cognitive disorders: recognition and management of delirium in the cardiovascular intensive care unit

Delirium is the most common acute cognitive disorder seen in critically ill patients in the cardiovascular intensive care unit. It is defined as a disturbance of consciousness and cognition that develops suddenly and fluctuates over time. Delirious patients can become hyperactive, hypoactive, or both. The occurrence of delirium during hospitalization is associated with increased in-hospital and long-term morbidity and mortality. The cause of delirium is multifactorial and may include imbalances in neurotransmitters, inflammatory mediators, metabolic disturbances, impaired sleep, and the use of sedatives and analgesics. Patients with advanced age, dementia, chronic illness, extensive vascular disease, and low cardiac output are at particular risk of developing delirium. Specialized bedside assessment tools are now available to rapidly diagnose delirium, even in mechanically ventilated patients. Increased awareness of delirium risk factors, in addition to non-pharmacological and pharmacological treatments for delirium, can be effective in reducing the incidence of delirium in cardiac patients and in minimizing adverse outcomes, once delirium occurs.