Hepatic encephalopathy

Clinical findings:

• • Asterixis (non-specific - also seen in other metabolic encephalopathies)
  • Seizures rare
  • Focal neurological deficits rare

Diagnosis

• • Exclude differential diagnoses
  • Ammonia levels are commonly elevated, but doesn't correlate with severity, and does not add prognostic or diagnostic value - don't check it
  • EEG always abnormal, but non-specific

Treatment

• • Lactulose
    • Increases ammonia clearance
    • Should improve symptoms within hours
    • Give at a dose sufficient to produce 2-3 soft bowel motions per day
  • Antibiotics
    • Rifamixin has proven efficacy in setting of lactulose use - 550mg BD
    • Both treatment and prophylactic
  • Polyethylene glycol
    • 4L orally/NGT
    • Improved faster than lactulose in acute encephalopathy
    • Not correlated with ammonia clearance rate
    • Unclear how it works
  • Dietary protein management
  • Hepatic encephalopathy in acute liver failure
    • Beware of cerebral oedema
      • 35% in grade 3, 75% in grade 4 encephalopathy
    • If patients with acute liver failure develop grade 2 encephalopathy, need ICU for monitoring and multiorgan support
    • Grade 3 - should be ventilated with head elevated to 30 degrees, consider mannitol/hypertonic saline