Delirium

Snapshot

• A 68-year-old man is brought by EMS to the emergency department from his retirement home. He was found to be excessively somnolent by his nurse earlier in the morning, prompting her to become alarmed and call for help. Upon presentation to the hospital, the patient is alert and oriented to self and correctly answers that he is at the hospital, but he states that the year is 1940. He is admitted to the inpatient unit overnight. The next day, the resident physician examines the patient multiple times during the morning and afternoon and finds that he is somnolent, difficult to arouse, and responds with only incoherent grunts before returning to a slumber. The patient’s medical history is significant for hypertension and hyperlipidemia.

Introduction

• Overview
  • delirium is characterized by a transient change of consciousness with waxing and waning confusion
• Epidemiology
  • prevalence
    • affects up to 10-30% of hospitalized adults
      • up to 80% of mechanically ventilated patients in the intensive care unit
  • demographics
    • ↑ prevalence in patients with older age, cognitive decline, and severe medical illness
    • extremely common among nursing home residents
• Pathophysiology
  • possible causes
    • certain medications (e.g., benzodiazepines) or drug toxicity (e.g., lithium)  
    • alcohol/substance intoxication or withdrawal
    • severe illness
    • malnutrition or dehydration
    • pain
    • sleep deprivation or severe emotional distress
    • anesthesia from surgery
• Prognosis
  • mortality rate among older patients in the hospital with delirium ranges from 20-75%
• some patients recover completely with adequate diagnosis and treatment

Presentation

• Symptoms  
  • fluctuating consciousness
  • disorientation
  • hallucinations (often visual)
  • illusions
  • disorganized thinking
  • disturbance in sleep-wake cycle
  • cognitive dysfunction
  • dysphasia
  • dysarthria
• tremor

Differential

• Major neurocognitive disorder
  • key distinguishing factor
    • acute onset of altered mental status
• Schizophrenia
  • key distinguishing factor
    • hallucinations are typically visual, with fluctuating level of consciousness
• Major depressive disorder
  • key distinguishing factor
• fluctuating level of consciousness, which is not seen in depression

Treatment

• Lifestyle
  • supportive therapy
    • reorientation and memory cues (e.g., calendar, clocks, and family photos)
    • ensuring a well-lit, quiet environment, preferably near a window for daytime/nighttime orientation
  • constant observation (e.g., sitter)
    • may help avoid use of physical restraints
• Medical
  • treating the underlying cause
    • stop potentially causative medications
    • multivitamins (especially thiamine) for patients with alcohol toxicity or withdrawal
  • antipsychotics (e.g., haloperidol and risperidone)
    • indication
      • treatment of choice for psychotic symptoms of delirium
  • benzodiazepines
    • indication
• treatment for alcohol and benzodiazepine withdrawal-induced delirium

Complications

• Malnutrition
• Falls
• Long-term cognitive impairment