ABSTRACT
Delirium is defined by the Diagnostic and Statistical Manual of Mental Disorders as an acute fluctuating disturbance in attention, environmental awareness, cognition, and perception. The incidence of delirium in patients admitted to an intensive care unit (ICU) ranges from 30 to 60%, of which 80% of cases occur in patients on mechanical ventilation. Once considered a temporary nuisance, delirium has since been shown to be associated with increased mechanical ventilation time, ICU length of stay, excess cost, worse long-term cognitive function, and increased mortality. Numerous pharmacological strategies for delirium prevention have been investigated, yielding inconsistent and conflicting data regarding the efficacy of any particular agent. The treatment of established delirium should be twofold: first to manage the behavioral disturbance, and secondly to find and treat the underlying medical disorder. Newer atypical antipsychotic agents such as quetiapine, risperidone, ziprasidone, and olanzapine have fewer side effects with similar efficacy, but their use has not been shown to prevent delirium in clinical trials.
