Delirium Etiologies

Acute change in mental status that fluctuates, abnormal attention, disorganized thinking and altered LOC

• Three criteria (A-C) are common to delirium caused by (1) a general medical condition, (2) substance intoxication, and (3) multiple etiologies:
  • Disturbance of consciousness (ie, reduced clarity of awareness of the environment) occurs, with reduced ability to focus, sustain, or shift attention.
  • Change in cognition (eg, memory deficit, disorientation, language disturbance, perceptual disturbance) occurs that is not better accounted for by a preexisting, established, or evolving dementia.
  • The disturbance develops over a short period (usually hours to days) and tends to fluctuate during the course of the day.

 CNS disorder

• Seizure
• Migraine
• Head trauma
  • Concussion
  • Contusion
  • Laceration
• Brain tumor 1⁰ or 2⁰
• Infection – meningitis or encephalitis
  • Viral – enterovirus
  • Bacterial – pneumococcal, meningococcal
  • Spirochette – syphilis
• Vascular
  • Arterial – transient ischemia, non-hemorrhagic stroke, hemorrhagic stroke, embolic stroke
  • Venous – subdural hematoma, thrombosis

Metabolic disorders and Endocrinopathies

• Electrolyte abnormalities
  • Potassium, Chloride, Magnesium, Manganese
• Fluid abnormalities
  • Dehydration
  • Intoxication
• Diabetes (hypoglycemia, hyperglycemia, insulin resistance)
• Adrenal abnormality
• Thyroid abnormality
• Parathyroid abnormality

 Neoplasm

• Primary brain
• Metastases
• Paraneoplastic syndrome

 Miscellaneous

• Intensive care unit psychosis
• Sleep deprivation

 Systemic illness

• Cardiac
  • Cardiac failure (CHF)
  • Arrhythmia
  • Myocardial infarction
  • Cardiac assist device
  • Cardiac surgery
• Pulmonary
  • COPD
  • Hypoxia
  • SIADH
  • Acid base disturbance
• Hematological
  • Anemia
  • Leukemia
  • Blood dyscrasia
  • Stem cell transplant
• Renal
  • Renal failure
  • Uremia
  • SIADH
• Hepatic
  • Hepatitis
  • Cirrhosis
  • Hepatic failure
• Infection (sepsis, abscess)
  • Viral: enterovirus
  • Bacterial: pneumonia (S. pneumoniae, H. influenzae, K. pneumoniae), UTI (E. coli)
  • Mycotic: aspergillosis
  • Spirochette: Lyme disease, syphilis
• Nutritional deficiency

 Medications and Toxins (use, intoxication, withdrawal)

• OTC (i.e. aspirin, Tylenol, ibuprofen, antihistamines, decongestants)
• Herbals (i.e. jimsonweed, oleander, foxglove, hemlock, dieffenbachia, Amanita phalloides)
• Heavy metals (i.e. , mercury, lead, arsenic, aluminum)
• Prescription medications
  • Pain medication (i.e. postoperative meperidine or morphine; lidocaine; barbiturates)
  • Anesthesia (i.e. ketamine)
  • Cardiac medications (i.e. digitalis, procainamide – arrhythmias)
  • Antihypertensives (i.e. methyldopa, reserpine)
  • Steroids
  • Antibiotics, antivirals and antifungals (i.e. amphotericin B, zalcitabine DDC, zidovudine AZT, pentamidine)
  • Sedative-Hypnotics (i.e. LA benzo’s – diazepam, flurazepam)
  • Histamine H2 antagonist (i.e. cimetidine)
  • Antineoplastic agents
  • Anticholinergic agents (i.e. Benadryl, TCA, diphenhydramine – insomnia)
  • Antituberculous agents
  • Antispasmotics (i.e. baclofen)
  • Ephedrine
  • Lithium
  • Contrast media
  • Colchicine (antigout)
  • Indomethacin
  • Levodopa
• Neuroleptic malignant syndrome
• Serotonin syndrome
• Abuse (intoxication or withdrawal)
  • Stimulants (i.e. crack/cocaine, amphetamines, methamphetamines)
  • Opiates (i.e. heroin, methadone, morphine, demerol)
  • Sedatives (i.e. EtOH, cannabinoids, marijuana, hashish)
  • Organic molecules (i.e. pesticides, insecticides, solvents/volatiles, gasoline, glue, ethylene glycol)