Neuro

Hepatic Encephalopathy

search

Hepatic Encephalopathy, Portosystemic Encephalopathy

  • See Also
  • Definition
  1. Brain dysfunction due to liver insufficiency or portosystemic shunting
  • Epidemiology
  1. Incidence: 30-40% of Cirrhosis patients within 5 years of Cirrhosis diagnosis
    1. Mild Impairment (Grade 1): 20-80% of cases
    2. Overt Hepatic Encephalopathy (Grades 2-4): 5-25% of cases
  • Pathophysiology
  1. Severe liver disease resulting in liver failure
  2. Inability to eliminate Neurotoxins
    1. Ammonia
    2. Mercaptans
    3. Fatty Acids
    4. Gamma-aminobutyric acid (GABA)
  3. Other mechanisms
    1. Astrocyte dysfunction
    2. Cerebral cellular swelling
    3. Blood-brain barrier disruption
  • Risk Factors
  • Precipitating Events
  1. Gastrointestinal Bleeding (especially Variceal Bleeding)
    1. Blood loss of 100 ml absorbed as 14-20 g Protein
  2. Azotemia
  3. Constipation
  4. High protein dietary intake
  5. Hypokalemic acidosis
  6. CNS Depressants (e.g. Benzodiazepines)
  7. Hypoxia
  8. Hypercarbia
  9. Sepsis or other acute infection
  • Findings
  • Symptoms and Signs
  1. Mild Disease (insidious onset)
    1. Day-night reversal
    2. Somnolence
    3. Confusion
    4. Personality change
    5. Asterixis (Flapping Tremor)
    6. Hypersalivation
  2. Severe Disease
    1. Stupor
    2. Coma
    3. Dementia
    4. Extrapyramidal signs
    5. Fetor hepaticus (Odor of breath from mercaptans)
  • Labs
  1. Markers correlated with Hepatic Encephalopathy
    1. International Normalized Ratio (INR)
    2. Venous total ammonia
    3. Ong (2003) Am J Med 114:188-93 [PubMed]
  2. Blood Ammonia Level (on ice)
    1. Not correlated with prognosis
    2. Normal ammonia level should prompt evaluation for other encephalopathy cause
  3. Consider Altered Mental Status Differential Diagnosis
    1. Comprehensive metabolic panel
    2. Blood Alcohol level
    3. Urine Toxicology Screening
    4. Serum Ketones
    5. Lactic Acid
  • Grading
  • West Haven Criteria Grading System
  1. Background
    1. Overt Hepatic Encephalopathy (OHE) seen in decompensated Cirrhosis refers to grades 2-4
  2. Grade 1
    1. Trivial lack of awareness
    2. Euphoria or anxiety
    3. Shortened attention span
    4. Impaired performance of addition or subtraction
  3. Grade 2
    1. Lethargy or apathy
    2. Minimal Disorientation for time or place
    3. Subtle personality change
    4. Inappropriate behavior
  4. Grade 3
    1. Somnolence to semi-stupor
    2. Responsive to verbal stimuli
    3. Confusion
    4. Gross Disorientation
  5. Grade 4
    1. Coma (unresponsive to verbal or noxious stimuli)
  6. References
    1. Ferenci (2002) Hepatology 335(3): 716-21 [PubMed]
  • Evaluation
  • Encephalopathy
  1. Consider Altered Mental Status Differential Diagnosis
    1. Hyponatremia
    2. Hypoglycemia
    3. Ketoacidosis
    4. Systemic infections
    5. Cerebrovascular Accident
    6. Closed Head Injury (e.g. Intracranial Hemorrhage)
    7. Intoxication or Toxin Ingestion
  2. Evaluate for underlying cause in new Hepatic Encephalopathy
    1. Gastrointestinal Bleeding (e.g. Variceal Bleeding)
    2. Portal Vein Thrombosis
      1. Obtain RUQ with doppler Ultrasound
    3. Infection (e.g. subacute Bacterial peritonitis)
      1. Tailored history and exam for underlying infection
      2. Obtain blood and Urine Cultures, serum lactate, and Paracentesis
      3. Consider Lumbar Puncture
  • Diagnostics
  • Management
  1. Initial Measures (effective in up to 90% of cases)
    1. ABC Management (especially airway)
    2. Avoid and correct precipitating factors listed above
    3. Reduce blood ammonia
      1. Lactulose (key management)
        1. Dose: 30-45 ml syrup PO titrated to qid or
        2. Retention enema 300 ml until >1 stool/day
      2. Decrease protein intake
        1. Limit to 20-30 g/day
        2. Protein restriction may not be needed
          1. Cordoba (2004) J Hepatol 41:38-43 [PubMed]
  2. Refractory cases
    1. Rifamaxin
    2. Neomycin 4-12 grams orally divided q6-8 hours
    3. Consider unproven or experimental methods
      1. IV branched chain amino acids
      2. Bromocriptine (may improve extrapyramidal symptoms)
      3. Flumazenil (may improve mental status)
      4. Lactilol (alternative to Lactulose)