Lecture 11 - Jaundice Flashcards
How does jaundice present itself?
Yellow discolouration of the skin, eyes and other tissues.
What causes Jaundice?
A buildup of bilirubin in tissue fluids and bloodstream.
How would you diagnose liver disease?
Performing liver function tests.
What levels would you look at on a liver function test?
- Bilirubin
- Liver enzymes (AST/ALT)
- Hepatobiliary enzymes (gGt/Alk, Phos)
- Albumin
- Total protein
- Autoantibodies/antibody titre
- Haematology
- Viral markers
- Metabolic indicators
- Tumour markers
How much bile is produced per day?
About 0.5L per day
What produces bile?
Hepatocytes
How often is bile recycled?
6-8 times a day to recycle bile salts
How much bile is stored in the gallbladder?
100ml
What is bile involved in?
- Released into the intestine on demand
- Emulsification of fat in the intestine
- Fat soluble vitamin uptake (A, D, E, K)
- Excretion of substances which can’t be cleared by kidney’s (cholesterol, bilirubin)
What is bilirubin a product of?
- Haem catabolism
- From red blood cells, myoglobin, cytochromes and peroxidases
How much bilirubin is produced per day?
250-300mg
What is the pathway of bilirubin?
- Transported to the liver carried by albumin
- In the liver, it is conjugated with glucuronic acid by UDP glucuronyltransferase (water soluble when conjugated).
- Metabolised by b-glucuronidase in the gut to form urobilinogens
- Some of these are reabsorbed and sent back to the liver and some are excreted in urine.
What are the steps of bilirubin metabolism?
(1) Production
(2) Uptake by the hepatocyte
(3) Conjugation
(4) Excretion into bile ducts
(5) Delivery to the intestines
What are the three causes/types of jaundice?
- Prehepatic
- Intrahepatic
- Extrahepatic
What causes pre-hepatic jaundice?
Conditions that heighten your blood’s rate of hemolysis. Because the bilirubin can only process so much bilirubin at once, bilirubin overflows into bodily tissues.
Symptoms of pre-hepatic jaundice?
Increased bilirubin (unconjugated) in blood but normal AST/ALT, normal ALP/gGT in the liver
Liver symptoms in anaemia?
- Gallstones
- Hepatomegaly, splenomegaly
- AST/ALT elevated
- Thrombosis
- Iron overload
- Hepatic thrombosis
- Coagulated deficit
- Altered MRI signal
What syndrome can prehepatic jaundice result in?
Gilbert’s Syndrome
Describe neonatal jaundice
- Up to 90% of babies, more if premature.
- Delays in clearance of bilirubin from red cell breakdown.
- Treated by phototherapy
- Only a concern if persists and is accompanied by pale stool/dark urine.
Describe hepatic jaundice
- Normal haem metabolism so normal bilirubin in the liver
- ## Increased bilirubin and raised AST/ALT and mild increase in ALP/gGT in the liver –> results in liver disease
What is viral hepatitis?
- Viruses selectively infect hepatocytes
- Very strong immune response causes severe hepatitis (A-E)
- Immune system then kills the infected hepatocytes
Describe post-hepatic jaundice
- Passage through the bile ducts are blocked
- Leaks into circulation
- Conjugated bilirubin is soluble so is excreted in the urine.
- Increased bilirubin, modest increase in AST/ALT, raised ALP/gGT
- Obstruction of bile ducts due to gallstones, disease of the ducts
