Jaundice - prof khan teaching Flashcards
Where is bile made?
LIVER
from right lobe & left lobe -> flow through right and left hepatic duct
Explain the duct system from right hepatic duct
RHD and LHD Common hepatic duct Cystic duct (from gall bladder) Common bile duct Via ampulla / sphincter of oddi
What is the function of the gall bladder?
STORAGE of bile
Which hormone is produced when someone eats fat? What happens when this hormone is produced?
Cholecystokinin hormone -> causes sphincter of oddi to relax, so ampulla opens
Also causes gall bladder to contract and squeeze
So bile is pumped into duodenum
What is another name for gall bladder pain?
Biliary colic
Where does bilirubin come from?
75% from RBC breakdown
22% from catabolism of other haem proteins
3% from ineffective bone marrow erythropoiesis
How is bilirubin transported from the spleen to the liver?
From the spleen, it is bound to albumin because it is insoluble
This is the UNCONJUGATED BILIRUBIN
How is bilirubin transported from the liver around the body? Explain the enzyme
As it’s dissociated from albumin in the liver, it has to be conjugated with glucoronic acid by UDPGT
Transported across concentration gradient into bile canaliculi
Where is the UDPGT made?
Smooth endoplasmic reticulum of hepatocytes
What is the resulting molecule that is water soluble when glucuronyl transferase conjugates bilirubin with glucoronic acid?
Diglucoronide bilirubin (water soluble)
What does diglucoronide bilirubin become when it is passed through urine?
Urobilinogens
What does diglucoronide bilirubin become when it is passed through stool?
Conjugated bilirubin in the colon is reduced by gut bacteria to stercobilinogen
oxidised to stercobilin (brown)
What do you call
Stercobilinogens (in stool)
At what point does a pt start looking yellow?
When bove 34
Prehepatic jaundice
Haemolysis (they're dying quicker than 120 days) e.g. from sepsis, AHA Massive transfusion Haematoma Resorption Infective erythropoeisis e.g. leukemia
Prehepatic jaundice caues
Increased quantity
Haemolysis (they're dying quicker than 120 days) e.g. from sepsis, AHA Massive transfusion Haematoma Resorption Infective erythropoeisis e.g. leukemia
What would you find on a blood investigations with prehaptic jaundcie?
Low hb levels due to haemolysis
High bilirubin but normal liver function tests because they don’t have to
Confirm via blood film to look for
Haptoglobins antibodies that cause haemolysis
Ask lab to do split bilirubin to work our conjugated vs unconjugated bilirubin
Hepatic/hepatocellular jaundice mechanism
Hepatocytes not working
Defective uptake/conjugation/excretion
Hepatic/hepatocellular jaundice causes
Acute/fulminant liver disease Acute on chronic decompensation Viral hepatitis Ethanol AID PBC PSC Intrahepatic cholecysteee?
Post hepatic jaundice causes
Obstruction
Defective transport of BR
Gall stones
Ca. cholangiocarcinoma, head of pancreas or hepatocellular carcinoma
Investigation findings for post hepatic jaundice / what would you investigate?
Negative haemolysis ALP and GGT high as they come mainly from biliary tree Dilated bile ducts on ultrasound CT or MRCP More conjugated bilirubin
What type of jaundice does gilbert’s syndrome cause?
hepatic jaundice
Inheritance pattern of Gilbert’s
Hereditary autosomal recessive condition
What percentage of people have gilbert’s?
5% of people will have it
What is the problem with Gilbert’s?
They’ve inherited an isoform of UDPGT that’s slow
UDPGT-1A1
UDPGT
Uridine diphsophate glucoronosyltransferase isoform 1A1
UDPGT full name
Uridine diphsophate glucoronosyltransferase isoform 1A1
Is the bilirubin mainly conjugated or unconjugated?
Mainly unconjugated because the UDPGT is slow
How would you diagnose Gilbert’s/what would you find on investigation
Liver disease screens negative, all normal
Predominantly unconjugated bilirubin
What would cause splenomegaly and low platelets?
PORTAL HYPERTENSION
What’s the normal size of the spleen?
Spleen should be normally around 12cm
What does decompensation mean?
Jaundice
Ascites
Variceal bleeding
Encephalopathy
What does decompensation mean?
Someone who has cirrhosis who develops:
Jaundice
Ascites
Variceal bleeding
Encephalopathy
What does it mean if cirrhosis is compensated?
Someone has cirrhosis but they don’t have:
Jaundice
Ascites
Variceal bleeding
Encephalopathy
What scan would you do to check for fibrosis?
Fibrescan
