approach to jaundice Flashcards
define jaundice
Hyperbilirubinaemia causing yellowing of body tissues
Bilirubin is a product of ___________________ metabolism
haemoglobin
Most of haemoglobin metabolism occurs in the _____________.
liver
Once conjugated in the liver, bilirubin enters the GIT at the _______________.
duodenum
Urobilin is excreted in …………….
urine
Stercobilin is excreted in ………….
faeces
List the 3 categories of jaundice
Pre-hepatic
Hepatic
post-hepatic
describe pre-hepatic jaundice
before the liver
relates to increase haemoglobin destruction –> increased bilirubin
e.g. IMHA
describe hepatic jaundice
the liver doesn’t do its job
reduced conjugation of bilirubin
describe post-hepatic jaundice
the conjugated bilrubin can’t exit via the biliary system
Describe what we see on haematology with pre-hepatic jaundice
anaemia - regenerative, macrocytic, hypochromic
blood smear- spherocytes , auto-agglutination
Name the 4 liver parameters
ALT
ALP
GGT
AST
when do you see ALT elevated
are from inside liver cells - hepatocytes
so increases due to hepatocellular damage
when do you see AST elevated
found in liver and muscle (skeletal and cardiac)
can be elevated due to jugular venepuncture and variety of other things
non-specific enzyme
when do you see ALP elevated
typically biliary tree
but also in bones and teeth
so can be increased due to dental disease
when do you see GGT elevations
if biliary disease
where is albumin made
liver
so low values may support liver disease
what happens to urea and ammonia values during liver disease
ammonia increases
urea decreases
due to urea cycle occuring in liver
List what is seen on liver function tests
Urea
Ammonia
Albumin
Clotting factors
Bile acid stimulation test (BAST)
Describe how we tell if jaundice is hepatic
biochemistry - ALP and ALT raised
Liver functioning tests
liver sampling
haematology
imaging
what is EHBDO
extrahepatic bile duct obstruction
what are the 3 types of extrahepatic bile duct obstruction
intraluminal obstruction
extramural
mural
List 5 causes of intraluminal obstruction that can cause post-hepatic jaundice
Cholelithiasis (stones)
Gall Bladder Mucocoele (Border Terriers)
Inspissated Bile
Gall bladder polyps
Cysts (Cats)
List 3 things that can cause extramural post-hepatic jaundice
pancreatic disease
duodenal disease
Porta hepatis stricture
describe mural post-hepatic jaundice
bile ducts are swollen
due to:
- inflammatory swelling
neoplasia
Describe how we tell if jaundice is post-hepatic on tests
liver function- largely normal
biochem- ALP and GGT raised disproportionally compared to ALT
haem- normal or inflam
imaging- will see distended biliary tree
