risk factors for delirium

Etiology

• advanced age (> 70 years)
  • elderly are sensitive to most medications
    • elderly frequently taking multiple medications
  • visual impairment**
  • hearing impairment, including cerumen impactation
  • vulnerable homeostasis mechanisms
• pre-existing central nervous system disease
  • prior history of dementia, cognitive impairment**
  • history of stroke, epilepsy
  • diminished cerebral perfusion or hypoxia
• uncontrolled pain
• recent surgery
  • depth of anesthesia
• use or dependence on CNS depressants
  • alcohol (alcohol abuse within 1 month)
  • hypnotics
  • opiates
• administration of psychoactive medications
• drug overdose or illicit drug use within a week
• severe illness (APACHE score > 16)**
  • infection
• sleep deprivation, sleep disturbance (common in hospitalized patients)
• transfer from a nursing home
• prior history of depression
• hypoxemia
• hypercarbia
• metabolic disorders & endocrine disorders
  • hyponatremia or hypernatremia
  • hypoglycemia or hyperglycemia
  • hypothyroidism or hyperthyroidism
  • hyperparathyroidism
  • Cushing's syndrome or adrenal insufficiency
• hypothermia or fever
• BUN/Creatinine ratio > 18, dehydration**
• organ failure
  • renal failure (creatinine > 2 mg/dL)
  • heart failure
  • live failure
• urinary retention (cystocerebral syndrome)
• liver disease (bilirubin > 2 mg/dL)
• history of congestive heart failure
  • volume overload
• elevated systolic blood pressure
• cardiogenic shock, septic shock
• HIV infection
• tube feeding
• rectal or bladder catheters
• central venous catheters
• malnutrition
  • thiamine deficiency
  • vitamin B12 deficiency
  • niacin deficiency
• use of physical restraints
• immobility
• no clock or calender
• frequent room changes
• surgery or trauma, ICU setting
  • lack of sleep, mechanical ventilation, severe pain
  • use of anxiolytics & analgesics
• total parenteral nutrition
• anemia

• table 2 of ref lists 33 predisposing factors associated with delirium
• table 3 of ref lists 112 precipitating factors associated with delirium

** one of 4 risk factors in predictive model for delirium in hospitalize elderly

* also see drugs commonly producing delirium

* prehospital statin therapy with continued statin therapy during hospitalization may diminish risk of delirium in critically ill elderly

Additional terms

• drugs commonly producing delirium