Delirium occurs in up to 50% of patients who are not mechanically ventilated and up to 80% of intensive care unit (ICU) patients who are mechanically ventilated. Even after controlling for preexisting morbidities, severity of illness, coma and use of sedatives, patients who develop delirium in the ICU are more than 3-times as likely to be dead at 6 months compared to those patients who do not develop delirium. (1-4) Additionally, ICU delirium is predictive of a threefold-higher reintubation rate and > 10 additional days in the hospital. (5) Each additional day of mechanical ventilation places patients at increased risk for life-threatening sequelae such as ventilator-associated pneumonia and barotrauma. The sequelae of delirium are cumulative; for example, each additional day spent in delirium is associated with a 20% increased risk of prolonged hospitalization and a 10% increased risk of death. Given these negative outcomes, it is not surprising that delirium is independently associated with substantially higher ICU and total hospital costs than for patients who do not develop delirium. (6) Up to a quarter of patients who develop delirium in the ICU develop long-term cognitive impairment that frequently manifests as dementia. (7-10) This post-ICU long-term cognitive impairment affects memory, attention, and executive function. It therefore compromises the ability to return to work, impairs activities of daily living, increases the need for institutionalization, and decreases quality of life. (11-13) More than 5,000,000 patients are admitted to an ICU in the United States each year. Delirium may develop in up 80% of these patients. (1, 2, 14) It is therefore critical that interventions that can prevent delirium from occurring in the ICU be discovered.