approach to jaundice

Question 1

define jaundice

Answer 1

Hyperbilirubinaemia causing yellowing of body tissues

Question 2

Bilirubin is a product of ___________________ metabolism

Answer 2

haemoglobin

Question 3

Most of haemoglobin metabolism occurs in the _____________.

Answer 3

liver

Question 4

Once conjugated in the liver, bilirubin enters the GIT at the _______________.

Answer 4

duodenum

Question 5

Urobilin is excreted in …………….

Answer 5

urine

Question 6

Stercobilin is excreted in ………….

Answer 6

faeces

Question 7

List the 3 categories of jaundice

Answer 7

Pre-hepatic
Hepatic
post-hepatic

Question 8

describe pre-hepatic jaundice

Answer 8

before the liver
relates to increase haemoglobin destruction –> increased bilirubin
e.g. IMHA

Question 9

describe hepatic jaundice

Answer 9

the liver doesn’t do its job
reduced conjugation of bilirubin

Question 10

describe post-hepatic jaundice

Answer 10

the conjugated bilrubin can’t exit via the biliary system

Question 11

Describe what we see on haematology with pre-hepatic jaundice

Answer 11

anaemia - regenerative, macrocytic, hypochromic
blood smear- spherocytes , auto-agglutination

Question 12

Name the 4 liver parameters

Answer 12

ALT
ALP
GGT
AST

Question 13

when do you see ALT elevated

Answer 13

are from inside liver cells - hepatocytes
so increases due to hepatocellular damage

Question 14

when do you see AST elevated

Answer 14

found in liver and muscle (skeletal and cardiac)
can be elevated due to jugular venepuncture and variety of other things
non-specific enzyme

Question 15

when do you see ALP elevated

Answer 15

typically biliary tree
but also in bones and teeth
so can be increased due to dental disease

Question 16

when do you see GGT elevations

Answer 16

if biliary disease

Question 17

where is albumin made

Answer 17

liver
so low values may support liver disease

Question 18

what happens to urea and ammonia values during liver disease

Answer 18

ammonia increases
urea decreases
due to urea cycle occuring in liver

Question 19

List what is seen on liver function tests

Answer 19

Urea
Ammonia
Albumin
Clotting factors
Bile acid stimulation test (BAST)

Question 20

Describe how we tell if jaundice is hepatic

Answer 20

biochemistry - ALP and ALT raised
Liver functioning tests
liver sampling
haematology
imaging

Question 21

what is EHBDO

Answer 21

extrahepatic bile duct obstruction

Question 22

what are the 3 types of extrahepatic bile duct obstruction

Answer 22

intraluminal obstruction
extramural
mural

Question 23

List 5 causes of intraluminal obstruction that can cause post-hepatic jaundice

Answer 23

Cholelithiasis (stones)
Gall Bladder Mucocoele (Border Terriers)
Inspissated Bile
Gall bladder polyps
Cysts (Cats)

Question 24

List 3 things that can cause extramural post-hepatic jaundice

Answer 24

pancreatic disease
duodenal disease
Porta hepatis stricture

Question 25

describe mural post-hepatic jaundice

Answer 25

bile ducts are swollen
due to:
- inflammatory swelling
neoplasia

Question 26

Describe how we tell if jaundice is post-hepatic on tests

Answer 26

liver function- largely normal
biochem- ALP and GGT raised disproportionally compared to ALT
haem- normal or inflam
imaging- will see distended biliary tree