45 Jaundice Flashcards
What happens to unconjugated bilirubin in the gut
unconjugated bilirubin is reduced by gut bacteria into tetrapyrroles called urobilinogens
True or false. Unconjucated bilirubin is always bound to albumin and not filtered in the urine
True. It is the conjugated bilirubin that is filtered and majority are reabsorbed in the proximal tubules
Yellowish discoloration resulting from the deposition of bilirubin
jaundice
Best site to examine slight increase in serum bilirubin
sclera for icterus
Why is the sclera the best site
Sclera have high affinity for bilirubin due to the high elastin content
What is the level of bilirubin for scleral icterus to manifest
Serum bilirubin of at least 3 mg/dl or 51 umol/L
Second best site to examine icterus
underneath the tongue
Other differential for yellowish discoloration of skin
carotenoderma, use of quinacrine, excessive exposure to phenol
Differential jaundice from carotenoderma
In jaundice, yellowish discoloration is distributed evenly throughout the body. In carotenoderma, pigment is concentrated in the palms, soles, forehead and nasolabial folds and sparing of the sclera
Breakdown product of heme
bilirubin
Source of 80-84% of bilirubin produced each day
Senescent of RBC
Where is the primary formation of bilirubin
Reticuloendothelial cells in the spleen and liver
Two chemical reactions in the formation of bilirubin
First: hemo oxygenase; Second: biliverdin reductase
What are the end products of the first reaction
biliverdin, carbon monoxide and iron
Responsible for the conjugation of bilirubin
UDPGT
What part of the GI tract hydrolyzes conjucated bilirubin to unconjucated bilirubin
At the distal ileum and colon, beta glucuronidases hydrolyze conjugated bilirubin to unconjugated bilirubin
True or false. In hemolytic disorders, serum bilirubin rarely exceeds 86 umol/L or 5 mg/dl
True. Higher levels are seen with co existent renal or hepatocellular dysfunction
Which Crigler- Najjar type is seen in neonates and which persists until adulthood
Crigler- Najjar Type I is rare as it is found in neonates with neurologic impairment due to kernicterus leading to death in infancy or childhood. Crigler- Najjar Type II live into adulthood
Represent a deficiency of the major hepatic drug reuptake transporters OATP1B1 and OATP1B3
Rotor syndrome
Causes of isolated indirect bilirubinemia
hemolytic disorders, ineffective erythropiesis, massive blood transfusion, resorption of hematoma, rifampicin, probenecid, ribavirin, protease inhibitors, Crigler-Najjar, Gilbert syndrome
Causes of isolated direct bilirubinemia
Dubin Johnson syndrome, Rotor syndrome
Periumbilical nodule that suggest abdominal malignancy
Sister Mary Joseph nodule
Interpretation of jaundice and low albumin
Suggests chronic process such as cirrhosis or cancer
Interpretation of jaundice and normal albumin
Suggests acute process such as viral hepatitis or choledocholithiasis
True or false. Failure of the prothrombin time to correct with parenteral administration of vitamin K indicates sever hepatocellular injury
True.
AST ALT ration in alcoholic hepatitis
AST ALT ratio of 2:1; AST rarely exceed 300 U/L
AST ALT values associated with hepatocellular disease
AST ALT values 25 times normal
Initial screening test for Wilsons disease
Ceruloplasmin
The next appropriate test to determine whether it is intra- or extrahepatic cholestasis
Ultrasound
Area difficult to visualize on ultrasound of hepatobiliary tree
distal common bile duct
Gold standard in identifying choledocholithiasis
ERCP
Drugs commonly associated with cholestatis
anabolic and contraceptive steroids
Autoimmune disease characterized by progressive destruction of interlobular bile ducts
Primary biliary cholangitis
How is primary biliary cholangitis diagnosed
Detection of antimitochondrial antibody
When does cholestasis of pregnancy occur
Second and third trimester of pregnancy and resolves after delivery
What trigger cholestasis in cholestasis in pregnancy
Triggered by estrogen administration
Intrahepatic stasis associated with renal cell cancer
Stauffers syndrome
Presents with highest surgical cure rates of all tumors that present as painless jaundice
Ampullary carcinoma
Most common cause of extrahepatic cholestasis
Choledocholithiasis
