Liver Failure Flashcards
Is liver failure acute or chronic?
It can be acute (often reversible) or chronic (irreversible)
Does the liver have a small or large functional reserve?
Large functional reserve (over 80% of its functional capacity must be lost before the organ completely shuts down)
Explain the mortality rate for liver failure.
High mortality rate -> over 50% of those with liver failure die as a result
Etiology of liver failure?
Cirrhosis, hepatitis C, Fulminent hepatitis, hepatotoxic drugs
What does hepatic insufficiency cause?
Multi-organ failure (kidney, heart, brain)
Name 4 areas of the body affected by liver cancer.
- hematology
- metabolism
- hepatorenal syndrome
- hepatic encephalopathy
Azotemia?
Increased amounts of nitrogen-containing compounds and wastes in the blood
Oliguria?
Small amounts of urine
How is hematology affected by liver failure?
- Defective hemostasis (clotting) due to decreased synthesis of clotting factors and fibrinogen which is a function of the liver.
- > additionally, there is inadequate clearance of clotting (with liver failure they remain active)
- > can lead to disseminated intravascular coagulation - The liver is involved with hematopoiesis by providing bone bone marrow with the building blocks for blood cells, so decreased function leads to a deficiency of blood cells.
- GI bleed -> portal HTN causes blood to back up into the GIT causing varies that can rupture.
DIC?
Disseminated Intravascular Coagulation = widespread clotting as a result of activated clotting factors that results in the formation of blood clots in the small vessels of the body (clots should only occur at the site of injury)
Why does anemia occur in liver failure?
Anemia occurs d/t RBC production and the production of dysfunctional RBC’s with membranes that are susceptible to lysing.
How is metabolism affected by liver failure?
- inadequate bilirubin clearance (excess bilirubin -> jaundice)
- Hypoalbuminemia = low levels of albumin in the blood (because the decreased OP causes a fluid shift out of the vessels and it does not have the pull pressure to bring it back in)
- Defective Urea cycle [the breakdown of proteins results in the production of ammonia, which is a toxic substance. The liver converts ammonia into a less toxic form (urea) which is then excreted. With decreased liver function there is a build up of ammonia and increase toxicity = hyperammonemia)
How is hepatorenal syndrome affected by liver failure?
- Idiopathic renal failure (mechanism is unclear as there is no structural or functional problem in the kidneys, however a direct link is shown (whenever liver failure is present, hypatorenal syndrome is present and when liver failure is absent, hepatorenal syndrome is absent)
- Severe renal ischemia (portal HTN results in increase of blood in the portal system, therefore less blood is circulating to the kidneys)
- Oliguria and Azotemia
How is hepatic encephalopathy affected by liver failure?
- even if the liver has some detoxifying function, blood bypasses the liver through alternative channels formed as a compensatory mechanism for portal HTN (portosystemic shunts)
- Toxic compounds (eg. ammonia) remain in the circulation and can travel to the brain, leading to hepatic encephalopathy.
Manifestations of hepatic encephalopathy.
Early manifestations: asterixis, hyperreflexia
- Confusion, coma and death r/t CNS failure
