14. Jaundice Flashcards
What 3 steps can bilirubin metabolism be summarised into?
Production of unconjugated bilirubin
Conjugation of bilirubin
Excretion of bilirubin
What is prehepatic jaundice?
Jaundice caused by excessive production of bilirubin
What is hepatic jaundice?
Jaundice due to pathology in the liver
What is posthepatic jaundice?
Jaundice caused by problems with biliary flow
What is obstructive jaundice?
Jaundice caused by lack of bile flow into the gut, resulting in pale faeces and dark urine
What is cholestatic jaundice?
Jaundice caused by bilirubin not flowing out the common bile duct, can be due to gallstones, ileus or common bile duct peristalsis due to certain drugs
What is unconjugated jaundice?
Jaundice caused by accumulation of unconjugated bilirubin due to excessive production of unconjugated bilirubin or decreased capacity to conjugate bilirubin
What causes increased production of bilirubin
Intravascular haemolysis which can be congenital- G6PD, PKD, sickle cell and thalassemia or acquired- artificial haeart valves, DIC, malaria
Extravascular haemolysis: congenital- hereditary spherocytosis and acquired- autoimmune haemolysis
What causes decreased conjugation of bilirubin?
Decreased hepatocyte uptake due to contrast agents and portosystemic shunts to bypass a cirrhotic liver
Congential enzymatic problems like Gilbert’s
What causes decreased excretion of bilirubin?
INVITED MD
Infection- hepatitis, ascending cholangitis, liver abscess
Neoplastic- mets, HCC, cholangiocarcinoma and pancreatic cancer
Vascular- Bud chiari syndrome
Inflammation- PBC, PSC, autoimmune hepatitis, pancreatitis
Trauma- gallstones, stricture after ERCP
Endo- intraheptic cholestasis of pregnancy
Degenerative- none
Metabolic- Wilson’s, haemachromatosis
Drugs- some drugs affect the ability of hepatocytes to excrete bilirubin- acohol, paracetamol, valproate and rifampicin. Some drugs cause biliary ileus- co amoxiclav, nitrofurantoin, OCP
What questions should you ask in the presenting complaint in someone with jaundice?
Is it acute/ chronic?
Associated symptoms:
RUQ pain, nausea, vomiting, pruritus (points towards hepatitis)
Fever or diarrhoea (also hepatitis/ abscess)
Steatorrhoea, dark urine (obstructive jaundice)
Weight loss, fever, night sweats (malignancy)
Bronzed skin (haemochromatosis)
Exposure to outdoor water/ sewage (risk factor for leptospirosis)
What should you ask in the PMHx in someone with jaundice?
Gallstones Liver disease Haemophilia Recent blood transfusion/ surgery Ulcerative colitis Diabetes Emphysema (suggests alpa 1 antitrypsin deficiency)
What should you ask about in the social history in someone with jaundice?
Excessive alcohol consumption Intravenous drug use Unprotected sex/ multiple partners Foreign travel Tattoos
