Table 1.

Risk factors for delirium [15]

Host factor	Acute illness	Iatrogenic and environmental factor
Age 65 years or older	Acidosis	Immobilization
Male sex	Anemia	Medication (e.g., opioids, benzodiazepines)
Alcoholism	Fever
Apolipoprotein E4 polymorphism	Infection	Anticholinergic drug
Dementia	Sepsis	Sleep disturbance
History of delirium	Metabolic disturbances (e.g., sodium, calcium, blood urea nitrogen, bilirubin)
Depression
Hypertension	Respiratory distress
Smoking
Vision or hearing impairment