[38] Jaundice Flashcards Preview

3: MED2 Y3 - Gastrointestinal [7] > [38] Jaundice > Flashcards

Flashcards in [38] Jaundice Deck (57)
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1
Q

What is the normal range of bilirubin?

A

3-17uM

2
Q

At what bilirubin level is jaundice visible?

A

50uM

3
Q

How is bilirubin produced?

A

Unconjugated bilirubin (uBR) is produced from the breakdown of haemoglobin by splenic macrophages

4
Q

What happens to uBR produced by splenic macrophages?

A

It is converted to conjugated bilirubin (cBR) by BR-UDP-glucuronyl transferase in the liver

5
Q

What happens to cBR after it has been produced in the liver?

A

It is secreted in the bile, then converted into urobilinogen

6
Q

What colour is urobilinogen?

A

Colourless

7
Q

What happens to urobilinogen in the GIT?

A

Some is reabsorbed

The urobilinogen that remains in the GIT is converted to stercobilin and excreted

8
Q

What colour is stercobilin?

A

Brown

9
Q

What happens to the urobilinogen that is reabsorbed into the liver?

A

It is returned to the liver and re-excreted into bile or urine

10
Q

What causes pre-hepatic jaundice?

A

Excess bilirubin production

11
Q

What can cause excess bilirubin production?

A

Haemolytic anaemia

Ineffective erythropoiesis

12
Q

Give an example of something that can cause ineffective erythropoiesis

A

Thalassaemia

13
Q

What are the categories of hepatic jaundice?

A

Unconjugated

Conjugated

14
Q

What causes unconjugated hepatic jaundice?

A

Decreased bilirubin uptake

Decreased bilirubin conjugation

15
Q

What can cause decreased bilirubin uptake?

A

Drugs

CCF

16
Q

Give 2 examples of drugs that can cause decreased bilirubin uptake

A

Contrast

Rifampicin

17
Q

What can cause decreased bilirubin conjugation?

A

Hypothyroidism
Gilbert’s
Crigler-Najjar

18
Q

What causes neonatal jaundice?

A

Increased production and decreased conjugation of bilirubin

19
Q

What causes conjugated hepatic jaundice?

A

Hepatocellular dysfunction

Decreased hepatic bilirubin excretion

20
Q

What are the categories of causes of hepatocellular dysfunction leading to conjugated hepatic jaundice?

A
Congenital 
Infection
Toxin
Autoimmune
Neoplasia
Vascular
21
Q

What are the congenital causes of hepatocellular dysfunction?

A

Heriditary haemochromotosis
Wilson’s
Alpha 1 anti-trypsin deficiency

22
Q

What are the infectious causes of hepatocellular dysfunction?

A

Hepatitis A/B/C
CMV
EBV

23
Q

What are the toxic causes of hepatocellular dysfunction?

A

Alcohol

Drugs

24
Q

What are the autoimmune causes of hepatocellular dysfunction?

A

Autoimmune hepatitis

25
Q

What are the neoplastic causes of hepatocellular dysfunction?

A

Hepatocellular carcinoma

Mets

26
Q

What are the vascular causes of hepatocellular dysfunction?

A

Budd-Chiari

27
Q

What are the causes of decreased hepatic bilirubin excretion?

A

Dubin-Johnson

Rotor’s

28
Q

What causes post-hepatic jaundice?

A

Obstruction

29
Q

What can cause obstruction leading to post-hepatic jaundice?

A
Stones
Pancreatic cancer
Drugs
PBC
PSC
Biliary atresia
Choledochal cyst (wtf is this????) 
Cholangiocarcinoma
30
Q

What are the mechanisms of drug-induced jaundice?

A

Haemolysis
Hepatitis
Cholestasis

31
Q

What drug causes jaundice through haemolysis?

A

Antimalarials, e.g. dapasone

32
Q

What drugs cause jaundice through causing hepatitis?

A
Paracetamol (in overdose)
Rifampicin, isoniazis, pyramizide (idk how you spell it, its the TB one) 
Valproate
Statins
Halothene
MOAIs
33
Q

What drugs cause jaundice through causing cholestasis?

A
Fluclox
Co-amox
OCP
Sulphonylureas
Chlopromazine
Prochloperazine
34
Q

What is Gilbert’s syndrome?

A

Partial UDP-GT deficiency

35
Q

What is the inheritance pattern of Gilbert’s syndrome?

A

Autosomal dominant

36
Q

What % of the population have Gilbert’s syndrome?

A

2%

37
Q

When does jaundice occur in Gilbert’s syndrome?

A

During intercurrent illness

38
Q

How is a diagnosis of Gilbert’s syndrome confirmed?

A

Increased unconjugated bilirubin on fasting

Normal LFTs

39
Q

What is Crigler-Najjar syndrome?

A

Rare condition with total UDP-GT deficiency

40
Q

What is the inheritance pattern of Crigler-Najjar syndrome?

A

Autosomal recessive

41
Q

What does Crigler-Najjar syndrome result in?

A

Severe neonatal jaundice

Kernicterus

42
Q

How is Crigler-Najjar syndrome managed?

A

Liver transplant

43
Q

What is found on urine testing in pre-hepatic jaundice?

A

No bilirubin

Increased urobilinogen

44
Q

When is increased Hb seen in urine testing in pre-hepatic jaundice?

A

If intravascular haemolysis

45
Q

What will be found on LFTs in pre-hepatic jaundice?

A

Increased uBR
Increased AST
Increased LDH

46
Q

What other tests should be done in pre-hepatic jaundice?

A

FBC and film
Coombs test
Hb electrophoresis

47
Q

What is found on urine testing in hepatic jaundice?

A

Increased BR

Increased urobilinogen

48
Q

What is found on LFTs in hepatic jaundice?

A
Increased cBR
Increased AST and increased ALT
Increased ALP
Decreased albumin
Increased prothrombin time
49
Q

What does a AST:ALT ratio of >2 indicate is the cause of hepatic jaundice?

A

Alcohol

50
Q

What does a AST:ALT ratio of <1 indicate is the cause of hepatic jaundice?

A

Viral

51
Q

What does increased GGT indicate is the cause of hepatic jaundice?

A

Alcohol or obstruction

52
Q

What other tests should be done in hepatic jaundice?

A

FBC
Anti-SMA, LKM, SLA, and ANA
Alpha1-AT, ferritin, and caeruloplasmin
Liver biopsy

53
Q

What may be found on FBC in hepatic jaundice?

A

Anaemia

54
Q

What is found on urine testing in post-hepatic jaundice?

A

Greatly increased bilirubin

No urobilinogen

55
Q

What is found on LFTs in post-hepatic jaundice?

A

Greatly increased cBR
Increased AST and increased ALT
Greatly increased ALP
Increased GGT

56
Q

What other investigations should be done in post-hepatic jaundice?

A

Abdominal US
ERCP and MRCP
Anti-AMA, ANCA, and ANA

57
Q

What may be found on abdominal US in post-hepatic jaundice?

A

Ducts >6mm