Hepatic encephalopathy

Hepatic encephalopathy is a worsening of brain function that occurs when the liver is no longer able to remove toxic substances in the blood.

Causes

Type Causes
Excessive nitrogen load Consumption of large amounts of protein, gastrointestinal bleeding e.g. from esophageal varices (blood is high in protein, which is reabsorbed from the bowel), renal failure (inability to excrete nitrogen-containing waste products such as urea), constipation
Electrolyte or metabolic disturbance Hyponatraemia (low sodium level in the blood) and hypokalaemia (low potassium levels)—these are both common in those taking diuretics, often used for the treatment of ascites; furthermore alkalosis (decreased acid level), hypoxia (insufficient oxygen levels), dehydration
Drugs and medications Sedatives such as benzodiazepines (often used to suppress alcohol withdrawal or anxiety disorder), narcotics (used as painkillers or drugs of abuse) and sedative antipsychotics, alcohol intoxication
Infection Pneumonia, urinary tract infection, spontaneous bacterial peritonitis, other infections
Others Surgery, progression of the liver disease, additional cause for liver damage (e.g. alcoholic hepatitis, hepatitis A)
Unknown In 20–30% of cases, no clear cause for an attack can be found

Symptoms

Symptoms many begin slowly and gradually worsen, or they may begin suddenly and be severe from the start.

Symptoms may be mild at first. Family members or caregivers may notice that the patient has:

  • Breath with a musty or sweet odor
  • Change in sleep patterns
  • Changes in thinking
  • Confusion that is mild
  • Forgetfulness
  • Mental fogginess
  • Personality or mood changes
  • Poor concentration
  • Poor judgment
  • Worsening of handwriting or loss of other small hand movements

More severe symptoms may include:

  • Abnormal movements or shaking of hands or arms
  • Agitation, excitement, or seizures (occur rarely)
  • Disorientation
  • Drowsiness or confusion
  • Inappropriate behavior or severe personality changes
  • Slurred speech
  • Slowed or sluggish movement

Exams and Tests

Tests may include:

  • Complete blood count or hematocrit to check for anemia
  • CT scan of the head or MRI
  • EEG
  • Liver function tests
  • Prothrombin time
  • Serum ammonia levels
  • Sodium level in the blood
  • Potassium level in the blood
  • BUN and creatinine to see how the kidneys are working

Treatment

Lactulose may be given to prevent intestinal bacteria from creating ammonia, and as a laxative to remove blood from the intestines. Neomycin may also be used to reduce ammonia production by intestinal bacteria. Rifaximin, a new antibiotic, is also effective in hepatic encephalopathy.