Surgical jaundice

Overview

Jaundice occurs in a variety of disease processes
Careful history and examination will often give clues as to the most likely underlying cause
Bilirubin metabolism is helpful to understand
Jaundice is classified into
- Pre-hepatic jaundice
- Hepatic jaundice (also called intrahepatic or hepatocellular jaundice)
- Post-hepatic jaundice (also called obstructive or cholestatic jaundice)
  - This is the type of jaundice seen in most surgical pathologies
  - Caused by obstructed bile outflow, leading to cholestasis
    - This means that bile cannot be excreted into the bowel, and then converted into urobilinogen and stercobilinogen - this causes stool to become pale
    - As bilirubin is still flowing into the liver and the liver is functioning (unlike in pre-hepatic or hepatic jaundice), soluble bilirubin is still being produced (and has nowhere to go)
      - This soluble bilirubin can then enter the urine, giving it a dark colour
  - The obstruction may be intrahepatic or extrahepatic
    - Intrahepatic obstruction
    - Extrahepatic obstruction
Liver function tests often aid classification as to whether jaundice is pre hepatic, hepatic or post hepatic.
The typical LFT patterns are given below:

	ALT/AST	ALP	Bilirubin
Pre-hepatic	Normal	Normal	Elevated
Hepatic	Elevated (often very high)	Elevated (but seldom very high)	Elevated
Post-hepatic	Elevated (moderate)	Elevated (very high)	Elevated