Jaundice Flashcards
What is jaundice?
This is a yellow tinge to the skin or the eyes (icterus) caused by a rise in the serum bilirubin >50 umol/L
It is important to distinguish jaundice from carotenaemia.
Classification of jaundice
Haemolytic jaundice
Congenital Hyperbilirubinaemias
Cholestatic jaundice
What is haemolytic jaundice?
Increased bilirubin for the liver cells.
Resulting jaundice is usually mild as the liver can compensate for the increased load.
Unconjugated bilirubin is not water-soluble and therefore doesn’t pass into the urine, hence ‘achlouric jaundice’
What is congenital hyperbilirubinaemia?
Defects in coagulation.
What is cholestatic jaundice?
Hepatocellular liver disease and bile duct obstruction.
Causes of haemolytic jaundice
Haemolytic anaemia: other features such as splenomegaly, gallstones and leg ulcers may be seen.
What would the investigations show in haemolytic anaemia?
Investigations show haemolysis and elevated unconjugated bilirubin.
Normal serum ALP, transferases and albumin.
Serum haptoglobin is low.
Causes of congenital hyperbilubinaemias
Gilbert syndrome- unconjugated type
Crigler-Najjar syndrome- unconjugated type
Dubin-Johnson and Rotor syndromes- conjugated type
Causes of cholestatic lunge (acquired)
Extrahepatic cholestasis- large duct obstruction of bile flow at any point in the biliary tract distal to the bile canaliculi.
Intrahepatic- occurs because of failure of bile secretion which may be caused by intrinsic defects in bile secretion or inflammation in the intrahepatic ducts.
Clinically in both types, there is jaundice with pale stools and dark urine.
The serum bilirubin is conjugated.
they MUST be differentiated as their clinical management is entirely different.
Clinical features of jaundice
Hepatomegaly (smooth, tender live is seen in hepatitis and in extrahepatic obstruction)
Splenomegaly
Ascites
Is jaundice a diagnosis?
Jaundice is not itself a diagnosis and the cause should always be sought.
What are the most useful investigations for jaundice?
Viral markers for HAV, HBV and HCV.
Ultrasound examination- this is to exclude an extrahepatic obstruction.
Ultrasound will demonstrate the size of bile ducts, which are dilated in extrahepatic obstruction and the level of obstruction.
Liver biochemistry- AST, ALT, ALP.
Biliary excretory function- serum bilirubin, urine bilirubin, serum bile acids, ALP, GGT.
Hepatocyte synthetic function- albumin, coagulation factors (PT and APTT)
Increased RBC destruction increases the level of unconjugated bilirubin.
Hepatocellular damage or biliary tract obstruction will cause elevated conjugated (direct) bilirubin levels.
Spped of onset of jaundice
Within days: Usually acute hepatitis caused by infection, alcohol or drugs.
Within a few weeks: More likely causes are subacute hepatitis or bile duct obstruction.
Fluctuating: drug-induced, ampullary carcinoma, gallstones
Associated symptoms of jaundice
Pain Pale stools Dark urine Anorexia, nausea and vomiting Weight loss Pruritus Fever
Pain with Jaundice
Pain- RUQ can be severe in patients with gallstones or alcoholic hepatitis.
Cholecystitis pain radiates to the right shoulder, right scapula or around the upper abdomen.
Invasive carcinoma of the head of the pancreas can cause epigastric pain radiating to the back.
Most causes of hepatocellular jaundice don’t cause significant pain.
