When the liver has been damaged by
cirrhosis, it may not be able to filter poisons from
the bloodstream, especially substances in the blood produced by bacteria in the
large intestine. As a result, these substances (which include ammonia) may
build up in the bloodstream and cause problems in your brain called
encephalopathy. High ammonia levels are a sign of encephalopathy.
Symptoms of encephalopathy may include:
Poor short-term memory.
Encephalopathy is most likely to occur in people who have high blood
pressure in the portal vein system (portal hypertension). But it may also occur in people who have severe acute
liver damage but do not have portal hypertension. Certain procedures (such as
shunting, which redirects the flow of blood or fluid through other areas of the
body) that help lower portal hypertension and prevent variceal bleeding may
actually increase your risk for encephalopathy. Other things that
can contribute to encephalopathy include use of sedatives or narcotics,
gastrointestinal bleeding, abnormal levels of
electrolytes in the blood (especially low potassium
levels), excess protein in the diet, infection such as
peritonitis, dehydration, and constipation.
Most cases of encephalopathy are treated using a medicine called
lactulose. This drug helps prevent the buildup of substances in the large intestine
that may lead to encephalopathy. Lactulose is effective at decreasing ammonia
levels in the blood and improving encephalopathy.