Delirium

Basics

Description

  • Delirium is a clinical syndrome characterized by acute changes in awareness, cognition, and perception with a waxing and waning course
  • Often secondary to an underlying acute medical condition
  • Multifactorial pathophysiology including neuroinflammation, brain vascular dysfunction, altered brain metabolism, and neurotransmitter imbalance
  • Frequently underrecognized by emergency medicine physicians
  • Associated with irreversible cognitive decline and increased risk of admission, hospital length of stay, and mortality

Etiology

  • Neurologic:
    • Meningitis or encephalitis
    • Seizure
    • Wernicke encephalopathy
    • Hypoxia and hypoperfusion of the brain
    • Intracranial bleed or mass
    • Stroke syndrome
  • Pulmonary:
    • Pneumonia
    • Other pulmonary etiology of hypoxia or hypercapnia
  • Cardiovascular:
    • Hypertensive crisis
    • Acute coronary syndromes
    • Arrhythmia
  • GI:
    • Hepatic encephalopathy
    • Dehydration
  • Renal:
    • UTI
    • Acute renal failure
  • Endocrine:
    • Hypoglycemia
    • Hyperglycemia
    • Hypothyroid
  • Rheumatologic:
    • Collagen vascular disorder
  • Toxicologic:
    • Medications or supplements
    • Withdrawal from barbiturates or alcohol
    • Environmental toxins
  • Other:
    • Electrolyte abnormalities
    • Vitamin deficiencies
    • Hypothermia
    • Hyperthermia
    • Trauma
    • Surgery

Geriatric Considerations

  • Common presentation in older ED patients
  • Up to 20% of older ED patients may have delirium
  • Many patients will present with subtle symptoms and vague chief complaints
  • Waxing and waning symptoms
  • Dementia is a significant risk factor for delirium
  • Long ED length-of-stay is a risk factor as well
  • May be a life-threatening condition

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