jaundice Flashcards
at what level is jaundice clinically detectable ?
when plasma bilirubin exceeds 40 umol/l or 2.5mg
which type of bilirubin is soluble and which type is insoluble ?
unconjugated - insoluble
conjugated - soluble
most of bilirubin is conjugated or unconjugated ?
unconjugated
what is
unconjugated bilirubin bound to ?
albumin
what enzyme is used for the conjugation of bilirubin in hepatocytes ?
UDPT
where is conjugated bilirubin excreted into ?
the bile and passees to the duodenal lumen
stercobilinogen vs urobilinogen ?
stercobilinogen is absorbed from the bowel and passes through the liver, through the kidneys to form urobilinogen
what are the causes of conjugated hyperbilirubinemia ?
parenchymal liver disease
intrahepatic cholestasis
extrahepatic cholestasis
what are the causes of unconjugated hyperbilirubinemia ?
too much bilirubin being produced extra-heaptically
impaired conjugation
main three causes of jaundice ?
pre hepatic
hepatic
post hepatic
other than pre and post hepatic what other broad classifications of jaundice are there ?
congenital hyperbilirubinemia
hemolytic jaundice
cholestatic ( whether intrahepatic or extrahepatic )
what are examples of congenital hyperbilirubinemia that cause conjugated hyperbilirubinemia ?
Crigler- najjar syndrome
Gilbert’s syndrome
what are the main causes of pre hepatic jaundice ?
caused mainly by haemolysis and congenital hyperbilirubinemia
what are the expected lab results for prehepatic causes of jaundice ?
unconjugated hyperbilirubinemia (isolated)
normal LFTS
elevated urobilinogen
jaundice due to hemolysis in adults vs newborns
in adults its mild
more aggressive in newborns
what is the most common cause of non hemolytic hyperbilirubinemia ?
Gilberts syndrome ( inherited)
what are the expected lab results in hepatic causes of hyperbilirubinemia ?
rise in both conjugated and unconjugated bilirubin
bilirubin in urine
what is the pathway of urobilinogen ?
retakeen up in the portal vein by the liver and then excreted by the kidneys
why is there dark urine in hepatic causes of hyperbilirubinemia ?
the liver loses the ability to re uptake the urobilinogen , so thee excess is excreted in the urine
what are the causes of intrahepatic cholestasis ?
viral hepatitis
drugs
cirrhosis
pregnancy
autoimmune cholangitis
what are the different causes of post hepatic hyperbilirubinemia ?
gall stones
tumor
biliary atresia
what type of bilirubin is raised in post hepatic hyperbilirubinemia ?
conjugated
eassociation of stercobilinogen and urobilinogen with post hepatic hyperbilirubinemia ?
low stercobilinogen
low urobilinogen
( clay coloured stool )
what are the expected lab results in post hepatic hyperbilirubinemia ?
elevated conjugated bilirubin
raised ALP and GGT
post hepatic jaundice is also called ?
obstructive jaundice
what are the lab findings in obstructive jaundice ?
raised conjugated bilirubin
raised ALT
raised GGT
what are the three labs used to assess liver function ?
Albumin
INR
Bilirubin