Delirium is highly prevalent in cancer patients with advanced disease. Frequently a preterminal event, the condition is a sign of significant physiologic disturbance, typically involving multiple medical etiologies including infection, organ failure, adverse medication effects, and in rare situations, paraneoplastic syndromes. Unfortunately, delirium is frequently unrecognized or misdiagnosed and, therefore, inappropriately treated or untreated in terminally ill patients. The clinical features of delirium are numerous and encompass a variety of neuropsychiatric symptoms common to other psychiatric disorders. Three clinical subtypes of delirium, based on arousal disturbance and psychomotor behavior, have been described: hyperactive, hypoactive, and mixed. The differential diagnosis for delirium includes depression, mania, psychosis, and dementia. Numerous instruments have been developed to aid the clinician in rapidly screening for the disorder. Standard management requires an investigation of the etiologies, correction of the contributing factors, and management of symptoms. Symptomatic and supportive therapies, including numerous pharmacologic approaches, are important, but several aspects of the use of neuroleptics and other agents in the management of delirium in the dying patient remain controversial.
