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Julian Raffoul, reviewed by Wesley Ely and Jo Ellen Wilson


  • Definition: acute fluctuating disturbance of attention and awareness due to an underlying medical condition

  • Presentation: deficits in attention, orientation, or memory; hallucinations or delusions; sleep-wake disturbances; psychomotor changes (hyperactive, hypoactive, or mixed); language impairment; and/or emotional lability (agitation)

    • Think about the ABC’s of Delirium

      • Affect (anxiety, paranoia, irritability, apathy, mood shifts, personality changes)

      • Behavior (hallucinations, restlessness or agitation, psychomotor abnormalities, sleep disturbances)

      • Cognition (impaired memory, disorientation, disturbances in speech)


  • Use screening tools to assess for delirium: Brief Confusion Assessment Method (bCAM). See critical care section for the ICU version, CAM-ICU

approach to delirium

  • Once delirium is diagnosed, evaluate for the underlying cause. Delirium has many etiologies and may occur alone or in combination (in ~10% of cases, no clear cause is found)

    • Mnemonic for common causes of delirium:

      • D- Drugs/toxins (use of benzodiazepines, opiates, anticholinergics, steroids, etc., withdrawal from ETOH, benzos, etc.)

      • E- Eyes/ears (sensory deficits)

      • L- Low perfusion states (MI, PE, heart failure, sepsis)

      • I- Infection

      • R- Retention (urine, stool)

      • I- Intracranial events (trauma, seizure, stroke, hemorrhage)

      • U- Undernutrition/dehydration

      • M- Metabolic, endocrine (Hypo or hyper Na, hyperCa, uremia, thyroid, hypoglycemia)

    • See neurology chapter for approach and work-up to AMS in general


  • Treat underlying cause as above

  • See critical care section for prevention in the ICU (ABCDEF bundle)

  • Cognitive impairment or disorientation: provide clock, calendar, and appropriate lighting. Regular reorientation. Provide cues from a familiar environment (pictures, calls or visits from family members)

  • Encourage mobilization

  • Review medications, eliminate sedatives and anticholinergics as able (review agents on Beers Criteria medication list)

  • Remove medical support devices as able (foley catheters, telemetry)

  • Maintain normal sleep-wake cycle. Keep lights on in the day and avoid excessive naps

  • Ensure adequate bowel regimen and hydration

  • Assess for pain and treat appropriately

  • Ensure hearing aids, glasses, and dentures are available

  • Note on pharmacologic management: There is no pharmacologic intervention known to prevent or treat of delirium. Reserve for agitation impairing patient safety when non-pharmacologic interventions alone are unsuccessful. See agitation section for medication approach