Delirium

Background

  • Acute disturbance of consciousness with fluctuating inattention and cognitive dysfunction
  • Caused by an underlying medical condition — NOT a primary psychiatric disorder
  • Extremely common: affects 10-30% of hospitalized elderly patients
  • Associated with increased mortality, prolonged hospitalization, and long-term cognitive decline
  • Key distinction from dementia: Delirium is acute (hours-days), fluctuating, with inattention as primary deficit; dementia is chronic (months-years) with memory as primary deficit

Clinical Features

  • Inattention — hallmark feature (cannot maintain or shift attention appropriately)
  • Fluctuating course throughout the day
  • Develops over hours to days (acute onset)
  • Subtypes:
    • Hyperactive: agitation, restlessness, hallucinations, combativeness (easier to diagnose)
    • Hypoactive: lethargy, decreased responsiveness, withdrawn (frequently missed — more common and more dangerous)
    • Mixed: alternating between hyperactive and hypoactive states

Common Causes (mnemonic: DELIRIUM)

  • Drugs (anticholinergics, opioids, benzodiazepines, steroids, polypharmacy)
  • Electrolyte abnormalities, Endocrine (thyroid, adrenal, glucose)
  • Lack of drugs (withdrawal from alcohol, benzodiazepines, opioids)
  • Infection (UTI, pneumonia, meningitis, sepsis)
  • Reduced sensory input (vision/hearing impairment, ICU environment)
  • Intracranial pathology (stroke, hemorrhage, mass, seizure)
  • Urinary retention, constipation (especially in elderly)
  • Myocardial/pulmonary (MI, PE, hypoxia, CHF)

Confusion Assessment Method (CAM)

  • Must have both features 1 AND 2 plus either 3 OR 4:
    1. Acute onset and/or fluctuating course
    2. Inattention
    3. Disorganized thinking
    4. Altered level of consciousness

Differential Diagnosis

Altered mental status

Diffuse brain dysfunction

Primary CNS disease or trauma

Psychiatric

General Psychiatric

Evaluation

  • Goal: identify and treat the underlying cause


AMS Workup

Common Orders


Consider Based on Clinical Situation

  • Blood and urine cultures
  • Ammonia level
  • Tylenol/Aspirin level
  • LP
  • Serum Osm
  • Coags
  • Cortisol
  • ABG/VBG
  • CO level
  • Minimum: glucose, BMP, CBC, urinalysis, ECG, CXR
  • Consider: LFTs, ammonia, TSH, blood cultures, lactate, urine toxicology screen
  • CT head if: focal neuro findings, fall/head trauma, anticoagulation, no clear cause identified
  • LP if meningitis/encephalitis suspected

Management

  • Treat the underlying cause — this is the definitive management
  • Non-pharmacologic measures first: reorientation, quiet environment, sleep-wake cycle preservation, mobilization, adequate hydration/nutrition, correct sensory deficits (glasses, hearing aids)
  • Pharmacologic (for severe hyperactive delirium with safety concerns):
    • Haloperidol 0.5-2 mg IV/IM (start low in elderly)
    • Olanzapine 2.5-5 mg IM
    • Avoid benzodiazepines (worsen delirium — exception: alcohol/benzo withdrawal)
  • Review and discontinue deliriogenic medications when possible

Disposition

  • Admit for workup and treatment of underlying cause
  • ICU if hemodynamically unstable, severe agitation, or respiratory compromise

See Also

References

Obtenido de «https://www.wikem.org/w/index.php?title=Delirium&oldid=389085»