jaundice

Question 1

Unconjugated bilirubin

Answer 1

Pre hepatic causes eg. Gilberts syndrome

Question 2

Conjugated bilirubin - cholestatic

Answer 2

Liver problems (hepatic)/ bile duct obstruction (post hepatic)

Question 3

types of jaundice

Answer 3

prehepatic/hemolytic
intrahepatic/hepatocellular
posthepatic/obstructive

Question 4

prehepatic/hemolytic jaundice

Answer 4

cause:
- excessive RBC breakdown

mechanism:
- increased unconjugated bilirubin production, exceeding liver capacity to conjugate it

common causes:
- hemolysis - eg sickle cell, G6PD deficiency
- Ineffective erythropoiesis eg thalassaemia
- haemolytic transfusion reactions

lab findings:
- inc in unconjugated bilirubin
- normal/inc urobillirubin
- no bilirubin in urine (bc unconjugated is water insoluble

Question 5

intrahepatic/hepatocellular jaundice

Answer 5

liver dysfunction

cause:
- impared billirubin metabolism / conjugation / uptake / excretion
- due to hepatocyte damage

common causes:
- hepatitis
- cirrhosis
- drug-induced liver injury
- liver tumors
- genetic disorder

lab results:
- inc in unconjugated
- inc in conjugated
- inc in ALT + AST
- dark urine
- possible pale stools if bile excretion is affected

Question 6

posthepatic/obstructive jaundice

Answer 6

biliary obstruction

impared excretion of conjugated biliruibin into the intestine

common causes:
- gallstones
- cholangiocarcinoma
- pancreatic cancer
- primary sclerosing cholangitis
- biliary atresia

test results:
- inc in conjugated bilirubin
- inc in ALP + GGT
- dark urine - conjugated bilirubin
- Pale stools due to lack of bile pigment
- pruritus - itching due to bile salt accumulation

Question 7

symptoms for each

Answer 7

prehepatic:
urine - normal
stools - normal
itching - no
liver tests - normal

hepatic / post-hepatic:
urine - dark
stools - pale
itching - maybe
liver tests - abnormal

Question 8

level of bilirubin

Answer 8

> 35umol/L

Question 9

symptoms for each jaundice

Answer 9

pre-hepatic:
- pallor
- fatigue
- exertional dyspnoea

intra-hepatic:
- anorexia
- fatigue
- nausea
- abdominal pain

post-hepatic:
- pale stools
- dark urine
- pritruitis
- steatorrhoea
- RUQ pain
- hepatomegaly

Question 10

investigations

Answer 10

liver enzymes AST/ALT - liver disease

Ultrasound - 90% have intrahepatic bile duct dilation visible on ultrasound

• CT
• magnetic resonance cholangiogram - MRI of biliary and pancreatic ducts
• endoscopic retrograde cholangiogram - endoscopy of biliary and pancreatic

Question 11

treatment

Answer 11

TREAT THE UNDERLYING CAUSE 
- Stop Drinking 
- Laparoscopic Cholecystectomy - surgery to remove the gallbladder using a camera and instruments - minimally invasive

Question 12

symptoms

Answer 12

Gall stones:
- Very common - 1/3 women over 60
Risk factors: 4F’s
Female
Forty
Fat
Fertile
Most are asymptomatic

Question 13

urobilinogen level in each

Answer 13

Pre = Urobilinogen is high
Intra/Post = Urobilinogen is low

Question 14

outline whole process of rbc breakdown

Answer 14

RBC

MACROPHAGE

HAEMOGLOBIN - into haem and globin

HAEM - BILIVERDIN

BILIVERDIN - UNCONJUGATED BILIRUBIN

into liver for conjugation

CONJUGATED BILIRUBIN

bile duct

bile secretion - duodenum

gut bacteria deconjugates bilirubin - urobilinogen

(some reabsorbed into blood - kidneys - urine)

most converted to stercobilin - excreted in faeces