Liver Failure and Jaundice Flashcards
What is the biliary tree
The structures responsible for transit and storage of bile
Define jaundice
describes the yellow discolouration of sclerae and skin due to raised bilirubin.
Detectable clinically when serum bilirubin >40µmol/litre.
What are the 3 main types of jaundice
Haemolytic jaundice
Jaundice caused by congenital hyperbilirubinamias
Cholestatic jaundice
Describe haemolytic jaundice
Pre-hepatic (before bilirubin reaches the liver)
Anaemias e.g. SCD, haemolysis, transfusion, haematoma resorption
Increase in break down of RBCs, increased unconjugated bilirubin production
Liver is normal
Increase in serum bilirubin
Describe jaundice caused by congenital hyperbilirubinaemia
Hepatic
Impaired conjugation of bilirubin OR bilirubin handling by the liver
Common = Gilbert’s syndrome
Describe Gilbert’s syndrome
Autosmal recessive
2-7% of population
Mutation in gene coding for UDP-glucoronyl transferase
Increase in unconjugated bilirubin
Asymptomatic, mild jaundice may appear under exertion, stress, fasting, infection etc.
Can lead to jaundice via dehydration, fasting and viral illness
Describe cholestatic jaundice and what is it characterised by
Post-hepatic
Failure/slow rate of bile secretion by the liver or bile duct obstruction
Characterised by conjugated bilirubin, pale stool, dark urine, abnormal liver biochemistry, sepsis
What are the two types of choelstatic jaundice
Intrahepatic cholestasis - caused by hepatocellular swelling or abnormalities at cellular lever of bile excretion.
Extrahepatic cholestasis - from the obstruction of bile flow at any point distal to the bile canaliculi (dilated bile ducts)
How does alcohol cause liver disease
Is a hapatotoxin Fatty change Alcoholic hepatitis Alcoholic cirrhosis exact mechanism unknown
What are the common causes of liver disease
Alcoholic and non-alcoholic fatty liver disease (developed)
Chronic viral Hep B or C (developing)
What are some other signs of liver disease
Hepatic encephalopathy - drowsy, coma due to toxin accumulation
Fetor hepaticus - must sweet breath odour
Hepatic flap - cours hand tremor
What is the aetiology of liver cirrhosis
Alcohol (developed) but Hep B and C (developing)
Response to chronic liver injury from any cause
What is used to diagnose liver cirrhosis
Liver biopsy
What is liver failure
Massive loss of hepatocytes or severe hepatic dysfunction occurring within 6 months of the symptoms of liver disease with clinical manifestation of hepatic encephalopathy or coagulopathy
What are the clinical features of acute liver failure
Jaundice CNS complications Coagulopathy Renal failure Sepsis Cardiovascular complications Metabolic complications
Describe sepsis due to acute liver failure
bacterial - occurs in 90%
Fungal - 32%
Commonly presents within 3 days of hospital admission
Fever and leucocytosis are absent
Describe the CNS complications of acute liver failure
Hepatic encephalopathy
toxin accumulation from the gut induces cerebral oedema -> consciousness and coma
Describe renal failure in relation to acute liver failure
hepatorenal syndrome - unexplained renal failure with liver disease or surgery for biliary tract obstruction
Kidneys are normal
Describe coagulopathy in relation to acute liver failure
Liver is important for coagulation
Impairs synthesis of coagulation factors I, II, V, VII, IX, X
Factor VII declines first
Fibrinogen only affected in severe disease
Increases fibrinolysis and coagulation
Decreased coagulation factor clearance
What suggests a coagulation defect
bleeding at any site
oozing at venepuncture sites - from excessive fibrinolysis
bruising (see photograph
Describe chronic liver failure
Deterioration in liver function superimposed on chronic liver disease
Cause may be infection, haemorrhage or electrolyte imbalance , alcohol
What can cause post-hepatic jaundice
Gall stones
Cancer
Cholangiocarcinoma
Describe the pathophysiology of liver failure
Rate of hepatocyte> regeneration
Apoptosis
Necrosis
What are the causes of acute liver failure
Disease of pregnancy e.g. AFLOP, Budd-Chiari
Idiosyncratic drug reactions e.g. NSAIDs
Vascular diseases e.g ischaemic hepatitis
Metabolic causes e.g. Wilson/s
