Jaundice

Question 1

What is jaundice?

Answer 1

Yellow discolouration of the sclera and skin.

Due to hyperbilirubinaemia occuring at levels of rougly >50 micromol/L

Question 2

Pathophysiology

Answer 2

High levels of bilirubin in the blood.

Bilirubin is the normal breakdown product from the catabolism of haem.

Bilirubin is normally conjugated within the liver -> water soluble

It is then excreted via the bile into GI tract.

Most will be egested in faeces as urobilinogen and stercobilin.

Around 10% of urobilinogen is reabsorbed into bloodstream and excreted through the kidneys.

Jaundice occurs when this pathway is disrupted.

Question 3

Types of jaundice

Answer 3

Pre-hepatic

Hepatic

Post-hepatic

Question 4

Explain pre-hepatic jaundice.

Answer 4

Excessive RBC breakdown which overwhelms that ability of the liver to conjugate

This leads to unconjugated hyperbilirubinaemia

The bilirubin that becomes conjugated will be excreted normally

The unconjugated remains in the blood to cause jaundice.

Question 5

Explain hepatocellular jaundice

Answer 5

Dysfunction of hepatic cells leading to loss of their ability to conjugate.

In case the liver becomes cirrhotic it compresses the intra-hepatic portions of the biliary tree leading to degree of obstruction.

This leads to both unconjugated and conjugated bilirubin in the blood

Question 6

Explain post-hepatic jaundice

Answer 6

Obstruction of biliary drainage

This leads to conjugated hyperbilirubinaemia

Question 7

Causes of pre-hepatic jaundice

Answer 7

Haemolytic anaemia

Gilbert’s syndrome

Criggler-Najjar syndrome

Question 8

Causes of hepatocellular carcinoma.

Answer 8

Alcoholic liver disease

Vira hepatitis

Iatrogenic via meds like TB medication

Hereditary haemochromatosis

Autoimmune hepatitis

PBC or PSC

Hepatocellular carcinoma

Question 9

Causes of post-hepatic jaundice

Answer 9

Intraluminal like gallstones

Mural causes like cholangiocarcinoma, strictures or drug-induced cholestasis

Extra mural like pancreatic cancer or abdo masses

Question 10

How can you determine which type of jaundice is present without investigations?

Answer 10

By bilirubinuria

Observe the colour of the urine

Question 11

Explain why observing the colour of urine can help in estimating what type of jaundice is present.

Answer 11

Conjugated bilirubin -> excreted via urine.

Unconjugated is not.

Dark/Coca-cola coloured urine is found in conjugated or mixed hyperbilirubinaemias.

Normal urine is seen in unconjugated disease.

Also post-hepatic usually leads to pale stools due to the reduced levels of stercobilin entering the GI tract.

Question 12

Lab tests

Answer 12

LFTs

Coagulation studies (PT can be used as a marker of liver synthesis function)

FBC (Anaemia, raised MCV, thrombocytopenia)

U&Es

Bilirubin

Albumin

AST and ALT

ALP

Gamma GT

Question 13

What liver screen is done in acute liver injury?

Answer 13

Hep A-E

CMV and EBV

Paracetamol levels

Caeruloplasmin

ANA and IgG subtypes

Question 14

Liver screen in chronic liver injury

Answer 14

Hep B and Hep C

Caeruloplasmin

Ferritin and transferrin saturation

Tissue Transglutaminase antibody (done in coeliac)

Alpha-1 antitrypsin

Autoantibodies (AMA, Anti-SA, ANA)

Question 15

Imaging done

Answer 15

US abdomen is usually first line.
This can find obstructive pathology or gross liver pathology.

MRCP (Magnetic Resonance Cholangiopancreatography) can be used to visualise the biliary tree.
It is used in obstructive jaundice if US abdo was inconclusive or limited.

Liver biopsy might be done if evretyhing else is inconclusive.

Question 16

What might gallstone need for management?

Answer 16

ERCP

Endoscopic Retrograde CholangioPancreatography

or

Stenting of the common bile duct

Question 17

Symptomatic treatment of jaundice

Answer 17

Often needed for the itching caused by hyperbilirubinaemia

Obstructive cause may warrant cholestyramine to increase biliary drainage

Some might just need anti-histamines.

Question 18

Other general management

Answer 18

Identify and manage any complications

Monitor for coagulopathy and treat promptly with either vitamin K or fresh frozen plasma (FFP) if there is any evidence of bleeding or rapid coagulopathy.

Treat hypoglycaemia orally if possible.

Question 19

What might be used when patients become confused from decompensating chronic liver disease (hepatic encephalopathy)?

Answer 19

Laxative like lactulose or senna +/- neomycin or rifaximin.

This is to reduce the number of ammonia-producing bacteria in the bowel

This is because constipation is a common cause of hepatic encephalopathy in decompensating chronic liver disease