12. Delirium

Definition

An acute decline in attention and cognition that follows a fluctuating course.  It is a common and potentially life-threatening condition that is potentially preventable. Features include:

  • Acute onset and a fluctuating course
  • Inattention and disorganized thinking
  • Altered level of consciousness with cognitive deficits
  • Perceptual disturbances (illusions or hallucinations)
  • Psychomotor disturbances (hyperactive-agitation/vigilance, hypoactive-lethargy, and mixed)
  • Altered sleep-wake cycle
  • Emotional disturbances

Etiology and Risk Factors

The cause of delirium is often multifactorial and involves the interrelationship between a vulnerable patient (one with predisposing factors) and exposure to precipitating factors or noxious insults.  Risk factors and precipitants:

  • Demographics: age>65, male sex
  • Cognitive Status: dementia, cognitive impairment, history of delirium, depression
  • Functional Status: functional dependence, immobility, history of falls
  • Sensory impairment: visual and hearing impairment.
  • Decreased oral intake: dehydration and malnutrition.
  • Medications: psychoactive medications, polypharmacy, alcohol abuse, anticholinergic medications, steroids, opiates, benzodiazepines, tricyclic antidepressants, propoxyphene, antihistamines (including H2 blockers).
  • Coexisting medical conditions: chronic renal or hepatic disease, prior stroke, metabolic derangements, terminal or critical illness, infection.
  • Surgery
  • Environmental: admission to an intensive care unit, use of physical restraints, use of bladder catheter, use of multiple procedures, pain, sleep deprivation and emotional stress.

Evaluation

  • Rule out depression, mania, acute psychosis
  • Use the confusion assessment method (CAM) to assess.
  • Investigate underlying causes: vital signs, medications, neurological examination, infections, intoxication/withdrawal.

Management

Prevention of delirium is the most effective strategy for reducing the frequency and complications of delirium. Once delirium occurs the key steps to management involve addressing all evident causes, providing supportive care, preventing complications and treating behavioral symptoms.

  • Non-pharmacologic Interventions:
    • Accompaniment (sitter, family members at bedside or via phone).
    • Normalize sleep/wake cycle by arranging for uninterrupted sleep (stop vital sign checks and lab draws overnight, open curtains during the day).
    • Mobilize patient and seat them in a chair with meals during the daytime.
    • Frequent re-orientation, with familiar objects from home if possible.
    • Minimize restraints.
    • Hearing/vision aids if not previously present.
    • Monitor I&Os, avoiding constipation and urinary retention.
  • Pharmacologic Interventions: reserved for patients with severe agitation who are a danger to themselves or others. Atypical antipsychotics, such as quetiapine, are often first line.
    • Schedule Melatonin 2 hours before bedtime to mimic a traditional sleep cycle.
    • Atypical Antipsychotics: EPS slightly less, some may prolong QT interval, associated with increased mortality rate among older patients with dementia.
      • Risperidone: 0.5mg twice daily.
      • Quetiapine: 12.5mg-25mg once at night or up to twice daily.
      • For an IV option, Ziprasidone 10 mg is an alternative to Haloperidol in patients with a normal QTc interval.
    • Typical Antipsychotics:
      • Haloperidol: 0.5mg-1mg twice-daily orally/intramuscularly, with extra doses every 4hrs as needed. Watch for QT prolongation or extrapyramidal symptoms (EPS), especially with doses >3mg/24h.
    • Benzodiazepines: often the precipitant of delirium and can make it worse, but can also temporarily calm patients who are agitated. Use only in patients undergoing sedative and alcohol withdrawal, neuroleptic malignant syndrome or Parkinson’s disease.
      • Lorazepam 0.5-1mg oral/IV q4hrs as needed.

Key Points

  • Delirium is common, detrimental and often preventable.
  • Prevention is the key to management.
  • Avoid giving medications for sedation unless the patient is a risk to themselves or others, including staff.
  • Low-dose antipsychotics are the first-line agents for management.
  • Benzodiazepines should only be used in the aforementioned situations due to their ability to worsen and precipitate delirium. 

Inouye, S. “Delirium in Older Persons.” N Engl J Med 2006; 354:1157-65

Wang, et el “Risk of Death in Elderly Users of Conventional vs. Atypical Antipsychotic Medications” N Engl J Med 2005; 353:2335-41.