Table 2.

Predisposing and precipitating factors for delirium^*

Predisposing Factors	Precipitating Factors
Dementia or pre-existing cognitive impairment	Medications: Polypharmacy Psychoactive medication use Sedative-hypnotic use
History of delirium	Use of physical restraints
Functional impairment	Use of bladder catheter
Sensory impairment: Vision impairment Hearing impairment	Physiologic and metabolic abnormalities: Elevated BUN/creatinine ratio Abnormal sodium, glucose, or potassium Metabolic acidosis
Comorbidity/severity of illness	Infection
Depression	Any iatrogenic event
History of transient ischaemia/stroke	Major surgery
Alcohol abuse	Trauma or urgent admission
Older age	Coma

^*From validated predictive models for delirium²