VPB 121: Veterinary Physiology - II (2+1)

Diagnostic differences between Haemolytic and obstructive jaundice

DIAGNOSTICS DIFFERENCES

Differntial diagnosis of haemolytic  and  obstructive  jaundice

• Vanden  Berg test is the specific test to differentiate free and conjugated bilirubin in the plasma. In the case of direct Vandenberg  reaction  Vandenberg  reagent  shows immediate reaction with   conjugated bilirubin.
• Free  bilirubin  in the presence of alcohol precipitates the protein and releases the  bilirubin, which reacts with   Vandenberg  reagent. Hence it is called as indirect Vandenberg test.          
• Indirect Vandenberg   reaction is the confirmatory test of haemolytic jaundice due to high content of free bilirubin in the plasma, whereas  obstructive jaundice can be confirmed by direct Vandeberg reaction due to increased content of conjugated bilirubin.
• In the case of total  obstruction of bile flow ,  lack of bilirubin in the intestine prevents the conversion of bilirubin    in to urobilinogen by bacterial action. Urobilinogen is not available for reabsorbtion through portal  blood and the excretion of urobilin through urine, henc test for  urobilinogen in urine is completely negative .
• The stools become clay coloured due to lack of  stercobilin and other bile pigments.  
• Kidney can excrete only highly soluble conjugated bilirubin but not the albumin bound "free bilirubin".
• In severe case of obstructive jaundice large quantities of conjugated bilirubin froms foam and becomes intense yellow colour while shaking the urine.