jaundice Flashcards
what is jaundice ?
yellowish discoloration of the skin and sclera due to buildup of bilirubin in the blood
at what level does does the yellow discoloration start to appear ?
when the bilirubin exceeds 40 Umol/l
2.5mg/dl
what is unconjugated bilirubin ?
insoluble bilirubin
what is conjugated bilirubin ?
soluble bilirubin
where does bilirubin come from ?
catabolism of haem from the breakdown of haemoglobin
what is insoluble bilirubinn bound to ?
albumin
what is the enzyme that catalyzes the reaction between conjugated and unconjugated bilirubin ?
uridine diphophoglucuronosyl transferase
how is stercobilinogen made ?
conjugated bilirubin is metabolized by colonic bacteria
what is urobilinogen ?
a small amount of stercobilinogen is absorbed from the bowel, passes through the liver and is excreted in the urine
what gives stool the brown colour ?
stercobillinogen
in total obstruction what would the colour of stool be?
clay coloured , loon elte7ena aw el 7alawa because there is no stercobilinogen
what are the causes of unconjugated hyperbilirubinaemia ?
excessive extrahepatic production
impaired conjugation/ impaired uptake
what are the causes of conjugated hyperbilirubinemia ?
parenchymal liver disease
obstruction of the biliary system
what are the possible causes of obstruction of the biliary system ?
such as cancer head of pancreas
what are the presentations of bilirubin in liver cirrohsis ?
both direct and indirect bilirubin are high
what is the most common cause of unconjugated hyperbilirubinemia ?
hemolytic jaundice
what are the different types of jaundice ?
pre hepatic
hepatic
post hepatic
what are the causes of pre haptic jaundice ?
haemolysis
congenital hyperbilirubinemia
what is the presentation of congenital hyperbilirubinemia ?
isolated bilirubin rise without LFTs abnormality
what is the most common form of non-haemolytic hyperbilirubinemia ?
Gilbert’s syndrome , diagnosis made by exclusion
how does hepato-cellular jaundice happen ?
results from an inability of the liver to transport bilirubin into the bile as a consequence of parenchymal disease
what can confirm that the cause of jaundice is hepato cellular?
if both direct and indirect bilirubin are high along with aminotransferase
what are the causes of intrahepatic cholestasis ?
viral hepatitis drugs cirrohsis pregnancy autoimmune cholangitis
what can be found in the urine inn cases of hepato-cellular jaundice ?
bilirubin in urine
why would we ask for a CBC in a patient with bilirubin n?
to check for hemolysis
what is an obstructive pattern ?
high GGT, alkaline phosphate and hyperbilirubinemia , mainly direct , mainly conjugated
what is the next best step in management after confirming an obstructive pattern ?
perform an ultrasound and if still nothing appears perform an MRCP
what is your first step in management after noticing a patient is jaundiced ?
ask for bilirubin
after asking for bilirubin levels of the patient what other tests should be asked for ?
direct bilirubin - ask for ALP GGT then UC, MRCP
indirect bilirubin - look for heamolysis through a CBC
if biphasic - ask for ALT AST , bilirubin , INR, Albumin
in obstructive jaundice which type of bilirubin is predominantly higher ?
indirect bilirubin
where is urobilinogen absorbed from ?
enterohepatic circulation
what is the typical presentation of a patient with gilbert’s syndrome ?
- bilirubin usually never exceeds 3
- defective uptake of indirect bilirubin
- with fasting bilirubin levels increase
