Approach to Patient with Jaundice Flashcards
How is heme converted to bilirubin?
Heme is converted to biliverdin then bilirubin in phagocytic cells
How is bilirubin transported to the hepatocytes?
Tightly bound to serum albumin
What happens to bilirubin after it reaches the liver?
The bilirubin from the blood is in unconjugated (insoluble) from and must be conjugated before it is secreted into the bile canaliculus as part of bile and then delivered to the small intestine
Hepatocyte function includes all of the following except:
- Drug detoxification
- Protein synthesis
- Gluconeogenesis
- Urea formation by deamination of amino acids
- Breakdown of hemoglobin
- Breakdown of hemoglobin
Which statement about the enterohepatic circulation of bile salts is true?
- The bile salt pool is re-circulated only at each meal
- In the normal individual, 50% of the bile salt pool must
be resynthesized and replaced daily - The rate of bile salt synthesis is subject to feedback inhibition, inversely proportionate to the amount of bile salts resorbed
- Bile salts are stored and diluted in the gallbladder
- The rate of bile salt synthesis is subject to feedback inhibition, inversely proportionate to the amount of bile salts resorbed
Bilirubinuria
Conjugated bilirubin is detected in the urine
What is the most common cause of bilirubinuria?
Most common cause is hepatocelular disease
Dubin-Johnson and Rotor syndrome
Inability of hepatocytes to secrete conjugated bilirubin into bile
Neonatal Jaundice
- Yellowing of the skin in a newborn
- Bilirubin level > 5mg/dL
What can lead to increased unconjugated bilirubin?
- Overproduction (hemolysis)
- Impaired uptake by the liver
- Abnormalities of bilirubin conjugation
What can lead to increased conjugated bilirubin?
- Hepatocellular disease (viral hepatitis, cirrhosis)
- Impaired canalicular excretion (drugs)
- Biliary obstruction (gallstones)
An icteric patient with sickle cell disease might be expected to have:
- Bilirubinuria
- Absence of urinary urobilinogen
- Cholesterol stones
- Unconjugated hyperbilirubinemia
- Unconjugated hyperbilirubinemia
Primary Biliary Cirrhosis
Destruction of intrahepatic bile ducts that leads to progressive cholestatic liver disease that is of autoimmune etiology
What Ab will be seen with Primary Biliary Cirrhosis?
Anti-mitochodrial Ab
Who most commonly gets Primary Biliary Cirrhosis?
Middle aged women