Jaundice Flashcards
Bilirubin physiology:
What is the breakdown product of haemoglobin?
What happens to this breakdown product?
What gives urine the yellow colour?
What gives stool a brown colour?
Unconjugated bilirubin created in the spleen
Conjugated in the liver making it water-soluble and allowing it to be excreted
Conjugated bilirubin is converted into urobilinogen which re-enters circulation and is excreted by the kidneys
The rest of the urobilinogen is converted into stercobilinogen
USE SLIDE 9 AND 11 - https://www.slideshare.net/madcatz21/bilirubin-metabolism-67992625
Over what level of bilirubin causes jaundice?
> 35 μmol/L
Pre-hepatic jaundice:
Cause - 2
What would you find in the serum of blood and urine when investigating?
Increased haemolysis (haemolytic anaemia) Impaired conjugation due to UDP-glucuronosyltransferase impairment (Gilbert's syndrome)
High levels of unconjugated bilirubin
High levels of urobilinogen
Hepatocellular jaundice:
Pathophysiology
Causes
Liver failure leads to impaired transport of bilirubin across hepatocyte into the bile duct
Liver disease - ALD, Viral hepatitis, autoimmune, drugs, haemochromatosis
Hepatocellular jaundice:
What does the stool look like and why?
What does the urine look like and why?
Normal stool - some conjugated bilirubin is still being produced so stool retains its colour
Dark pee - elevated levels of unconjugated bilirubin being excreted as not enough are being conjugated by the liver and the spleen is still producing unconjugated B from haemoglobin.
Its dark colour is what it would look like without urobilinogen
Hepatocellular jaundice:
What would you find in the serum of blood and urine when investigating?
High levels of conjugated and unconjugated bilirubin
Some urobilinogen and conjugated bilirubin
Obstructive (cholestatic) jaundice:
Pathophysiology
Obstruction of biliary tree or portal ducts leads to conjugated bilirubin not entering the GI tract and backing up into the circulation and then kidneys
Obstructive (cholestatic) jaundice:
Extra-hepatic:
- Luminal (inside lumen) - 1
- Mural (in the wall itself) - 2
- Extra-mural (from the outside) - 2
What is mirizzi’s syndrome? - pics
Gallstones
Cholangiocarcinoma Biliary strictures (iatrogenic, primary sclerosing cholangitis, pancreatitis)
Pancreatic head tumour
Enlarged porta hepatis lymph nodes
Common hepatic duct obstruction caused by extrinsic compression from an impacted stone in the cystic duct or infundibulum of the gallbladder
Obstructive (cholestatic) jaundice:
Intra-hepatic:
Primary biliary cholangitis (PBC) - define?
Primary sclerosing cholangitis - define?
Autoimmune disease of the liver. It results from a slow, progressive destruction of the SMALL BILE DUCTS OF THE LIVER, causing bile and other toxins to build up in the liver, a condition called cholestasis.
A long-term progressive disease of the liver and gallbladder characterized by inflammation and scarring of the bile ducts which normally allow bile to drain from the gallbladder.
Obstructive (cholestatic) jaundice:
What might happen in pregnancy?
What else is important that should be asked about in the history?
Obstetric cholestasis - a disorder that affects your liver during pregnancy. This causes a build-up of bile acids in your body.
Drugs - meds
Obstructive (cholestatic) jaundice:
What does the stool look like and why?
What does the urine look like and why?
What’s another symptom they will have?
Pale stool - Less urobilinogen is available so less stercobilinogen
Dark urine - less conjugated bilirubin, therefore, less urobilinogen is available to be excreted by kidneys
Itch due to build up of bile salts - not bilirubin
Obstructive (cholestatic) jaundice:
What would you find in the serum of blood and urine when investigating?
What else might you need to reach a diagnosis about where the blockage is?
High conjugated bilirubin backed up into the blood
Low levels of urobilinogen and high conjugated bilirubin
US, MRCP and CT
Obstructive (cholestatic) jaundice:
Medical management
What can be done by an ERCP?
What is an PTC?
IV fluids
Vit K
Antibiotics for cholangitis
Sphincterotomy, clearance and stenting
Percutaneous transhepatic cholangiography - a radiological technique used to visualize the anatomy of the biliary tract. A contrast medium is injected into a bile duct in the liver, after which X-rays are taken.
Obstructive (cholestatic) jaundice:
Complications
Coagulopathy due to impaired Vitamin K absorption in the gut - High INR
Hepatorenal syndrome
Acute cholangitis
What should you ask a patient with jaundice in a history?
Blood transfusions IV drug use Piercings Tattoos Sexual activity Travel abroad FH Alc use Drugs
