How to tell the difference between obstructive and nonobstructive jaundice

In a patient with increased bilirubin there are 2 types. Conjugated and unconjugated. With those 2 types it’s pretty easy to figure out what type of problem is causing the abnormality.

Nonobstructive (bile duct not blocked)

Pre hepatic (does not involve the liver)

Caused by the breakdown of red blood cells.

  • Malaria
  • Sickle cell anemia
  • Thalassemia

These cause the breakdown of red blood cells. This in turn causes a pre hepatic non obstructive jaundice.

Pre hepatic shows and increase in unconjugated bilirubin because the bilirubin does not make it to the liver to be processed (conjugated).

With these diseases the amount of bilirubin the body produces is increased. So the bilirubin will show conjugated as long as the liver can keep up. But as the body creates more and more it will surpass the livers ability to process the bilirubin and the levels of unconjugated bilirubin will increase.

If it does involve the liver then it’s hepatocellular. So these are disease processes that directly involve the liver. Think acute or chronic hepatitis. Hepatotoxicity. cirrhosis. The actual liver cells are damaged so they do not metabolize the bilirubin.

Again you see an increase in unconjugated bilirubin because the liver cells are sick and unable to process the bilirubin.

Shotgun SignObstructive (bile duct blocked)

Post hepatic

If you see an increase in conjugated bilirubin that means that the liver is functioning correctly and secreting the bile it is just being hindered somewhere. Obstructed.
So we look for an obstruction.

  • Bile Duct Stone or obstruction
  • Pancreatic head mass
  • Hepatocellular carcinoma (may obstruct the ducts within the liver and hinder the flow)

So to summarize, if the bilirubin is conjugated the bilirubin made it to the liver but was obstructed from leaving. If it’s unconjugated then the disease is either involving the blood or the livers ability to process the bilirubin.

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