Delirium | Medical Council of Canada
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Version: March 2023
Legacy ID: 58-2


Delirium is a disturbance of cerebral function secondary to an underlying medical condition. Delirium is extremely common in hospitalized patients. The presenting syndrome is an altered level of consciousness, impaired cognition, and reality testing with a fluctuating course. Delirium is associated with increased risk of death, prolonged hospitalization, and institutionalization.

Causal Conditions

(list not exhaustive)

  1. Medications (e.g., sedative, anticholinergic)
  2. Metabolic (e.g., fluid and electrolyte disturbance)
  3. Hypoxia (e.g., anemia, hypoperfusion)
  4. Infection
  5. Endocrine (e.g., hypothyroidism)
  6. Neurological (e.g., stroke, dementia, infection)
  7. Postsurgical
  8. Withdrawal (e.g., alcohol, benzodiazepines)
  9. Trauma

Key Objectives

Given a patient with delirium, a candidate will recognize the syndrome, diagnose the cause(s), and will initiate an appropriate management plan. Particular attention should be paid to the urgent nature of the condition.

Enabling Objectives

Given a patient with delirium, a candidate will

  1. list and interpret critical clinical findings, including those derived from
    1. the identification of susceptibility factors for delirium (e.g., age, alcohol use disorder, dementia);
    2. the use of appropriate diagnostic clinical tools (e.g., Mini–Mental State Examination); and
    3. a comprehensive history—including collateral history from family and caregivers—and an appropriate physical examination aimed at eliciting the cause of delirium;
  2. list and interpret critical investigations, including appropriate laboratory investigations and diagnostic imaging (e.g., blood gases, blood culture, computerized tomography scan); and
  3. construct an effective initial management plan, including
    1. instituting acute management of underlying conditions, as appropriate;
    2. ensuring appropriate treatment of agitation and sleep disturbance;
    3. managing the environment of the patient to assist in reorientation and settling; and
    4. seeking clarification of proxy decision-making while the patient is incapacitated.