Hepatic encephalopathy is brain dysfunction caused by liver failure, when toxins such as ammonia build up in the blood instead of being cleared by the liver. It ranges from subtle sleep and attention problems to coma, and it is usually set off by a trigger.
Key symptoms
- Confusion, forgetfulness or poor attention
- Sleep reversal: sleepy by day, awake at night
- Personality change or irritability
- Drowsiness that can progress to coma
What you find on exam
- Asterixis (flapping tremor of the outstretched hands)
- Level of consciousness and orientation
- Signs of liver disease: jaundice, ascites, spider angiomas
- Look for triggers: bleeding, infection, dehydration
Tests
- Liver function tests, INR, electrolytes, kidney function, glucose
- Blood count and stool check for gastrointestinal bleeding
- Diagnostic paracentesis if ascites, to rule out peritonitis
- CT head if there is a fall, focal signs or doubt about the cause
Treatment basics
- Find and treat the trigger: infection, bleeding, constipation, sedatives, low potassium
- Lactulose to reach 2 to 3 soft stools a day
- Add rifaximin for recurrent episodes
- Protect the airway in deep coma; stop sedatives
Red flags
- Deepening coma or unable to protect the airway
- Vomiting blood or black stools
- Fever or abdominal pain suggesting infected ascites
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.