Jaundice Flashcards
Describe the production, conjugation and excretion of bilirubin.
Produced from breakdown of haem
Insoluble in initial form so must be conjugated in the liver
Majority of conjugated bilirubin is excreted via the biliary system in faeces, small amount is excreted renally
What is jaundice?
Yellow discolouration (icterus) of the sclera or skin due to raised serum bilirubin
What are the three types of jaundice?
Pre-hepatic
Intrahepatic
Post-hepatic
What is the mechanism of pre-hepatic jaundice?
Increase in bilirubin production due to increased RBC breakdown
What is the mechanism of intrahepatic jaundice?
A failure to conjugate bilirubin in a damaged/inflamed liver, or a failure to excrete it into the bile ducts
What is the mechanism of post-hepatic jaundice?
Failure to remove the conjugated bilirubin via the biliary system
What are the causes of pre-hepatic jaundice?
Autoimmune haemolysis Hereditary spherocytosis G6PD deficiency DIC Extensive bruising, large haematomas
What are the causes of intrahepatic jaundice?
Decompensated chronic liver disease, cirrhosis, AFLD, NAFLD, haemochromatosis
Acute liver injury e.g. drug overdose, viral hepatitis
Drugs
Errors of bilirubin metabolism e.g. Gilberts
What are the causes of post-hepatic jaundice?
Mechanical obstruction of the large bile ducts e.g. cholangitis, cholangiocarcinoma, pancreatic cancer
Drug- or pregnancy-induced cholestasis
Autoimmune disease e.g. PBC, PSC
What are the symptoms of pre-hepatic jaundice?
Symptoms of anaemia e.g. SOB, syncope, fatigue, pallor
Jaundice + anaemia = haemolysis
What are the risk factors for development of chronic liver disease?
Viral hepatitis Alcohol excess Obesity T2DM Family history Hx of other autoimmune conditions Intercurrent infections, upper GI bleeds --> decomensation of cirrhosis
What are the risk factors for development of acute liver injury?
Paracetamol overdose
Acute HAV/HEV infection
Alcohol binge
What are the symptoms of post-hepatic jaundice?
Pale stools, dark urine
RUQ/epigastric pain –> cholangitis
Weight loss –> obstructing malignancy
Painless jaundice –> pancreatic malignancy
What bloods should be taken from a patient with jaundice?
FBC Haemolysis screen LFTs CA19-9, CEA, CA125 Lactate CRP Coag
Which imaging modalities can be used to diagnose a cause of jaundice?
US abdomen –> duct dilatation, cirrhosis, gallstones
CTAP –> pancreatic masses
MRCP –> bile ducts, small stones and strictures
ERCP –> removal of stones, biopsies
