Dexmedetomidine and delirium in the ICU

Delirium is a common problem encountered in the care of critically ill patients. It is characterized by an acute onset of impaired cognitive functioning that has a fluctuating course with impairment in a patient’s ability to process information (1). There are many proposed pathophysiologic mechanisms for delirium including decreased cholinergic activity, increased dopaminergic activity and changes in serotonergic activity (2). ICU patients seem to be at high risk of developing delirium. There are many risk factors for the development of delirium that commonly occur in ICU patients including fever, sepsis, pressor requirements and the use of medications such as benzodiazepines, opiates and anticholinergics (2). Mechanically ventilated patients appear to be at especially high risk for developing delirium during their stay in the ICU (1). There is strong evidence that in mechanically ventilated patient’s delirium is an independent predictor of mortality and prolonged hospitalization (3). Delirium during ICU admission has been shown to have significant long-term impact on cognitive functioning after ICU discharge (4). Additionally, there appears to be a correlation between the duration of delirium and cognitive dysfunction after ICU discharge (4). Nonpharmacological interventions, such as physical and occupational therapy and control of noise pollution decrease delirium duration and are widely recommended (2). Haloperidol is the traditional agent for the pharmacological treatment of delirium; second-generation antipsychotics have been used as an alternative treatment (2). However, the studies evaluating these agents are generally limited by small sample size. A recent randomized controlled trial in 142 critically ill patients requiring mechanical ventilation demonstrated that haloperidol did not modify the incidence or duration of delirium (5). Given the significant burden of delirium in the ICU, new strategies to both prevent and treat delirium in the ICU are needed to address this complication and improve long-term outcomes in ICU patients