Jaundice DSA - McGowan Flashcards
transfusion reactions, sickle cell anemia, thalassemia (inadequate Hg), autoimmune disease
prehaptic
hepatitis, cancer, cirrhosis, congenital disorders, drugs
intrahepatic
gallstones, inflammation, scar tissue or tumors that block the flow of bile into the intestines
posthepatic
primary injury is to the hepatocytes
- primarily AST/ALT elevation
- ALT more specific for liver injury than AST
hepatocellular injury
primary injury is to the bile ducts
- primarily Alk Phos and bilirubin elevated
- failure of bile to reach duodenum
- jaundice and pruritis
- pure cholestasis (no signs of hepatocellular necrosis)
cholestatic injury
what are the TRUE liver function tests that McGowan wants us to know?
NOTE: AST/ALT, Alk Phos and bilirubin (LDH, GGT) can come from other sources and are not accurate to determine liver’s function
- PT/INR
- albumin
- cholesterol
- ammonia
what are the 4 main DDx for unconjugated (indirect) jaundice?
- hemolytic syndrome (anemia/reaction)
- Gilbert syndrome
- Criggler-Najjar syndrome
- viral hepatitis
what are the 5 main DDx for conjucated (direct) jaundice?
- hepatitis (acute/chronic, infectious/non-infectious)
- cirrhosis
- obstruction
- Dubin-Johnson syndrome
- Rotor syndrome
what are the first steps in evaluating pt with jaundice?
- determine conjugated vs unconjugated
2. other biochemical liver tests are normal
how to diagnose jaundice
- order CBC to look for anemia and thrombocytopenia
- order chemistry labs: AST/ALT, total bilirubin, Alk phos (will need to request fractionated bilirubin to tell you indirect vs. direct)
when ALP is elevated, what is your next step?
fractionate by ordering gamma glutamyl transferase (GGT)
what if ALP and GGT are elevated?
most commonly coming from liver source
what if ALP elevated, but GGT is normal?
consider bone or other source (placenta) for elevated ALP
what would you order to look for anemia and thrombocytopenia?
CBC
- can check for hemolysis: haptoglobin (low), reticulocyte count (elevated) and LDH (elevated)
reduced activity of uridine diphosphate glucuronyl transferase
- unconjugated (indirect) bilirubin
- benign, asymptomatic hereditary jaundice, hyperbilirubinemia increased by 24-36 hour fast
Gilbert syndrome
- no tx required
- assoc with reduced mortality from cardiovascular disease
AR, absent UGT1A1 activity
- no liver pathology
- fatal in neonatal period
Crigler-Najjar Type 1
AD with variable penetrance, decreased UGT1A1 activity
- no liver pathology
- generally mild, occasional kernicterus
Crigler-Najjar Type 2
AR, decreased UGT1A1 activity
- no liver pathology
- innocuous (not harmful) clinical course
Crigler-Najjar Type 3
AR, impaired biliary excretion of bilirubin glucuronides due to mutation in canalicular multidrug resistance protein (MRP2)
- pigmented cytoplasmic globules
- innocent clinical course
Gilbert Syndrome
what is the main serum antibody present in acute viral hepatitis?
IgM
what is the main serum antibody present in chronic?
IgG
viral, drugs, ischemia, Budd-Chiari
- pt has aversion to smoking
- stools my be acholic (no bile = pale yellow)
- dx: CVC, CMP, PT/INR, acetaminophen level (use rumack-matthew nomogram)
acute hepatitis
- ssRNA virus
- aversion to smoking
- 2-3 week incubation
- enlarged tender liver, jaundice, acholic stools
- fecal-oral transmission
- elevated bilirubin and alk phos = cholestasis
- both IgM and IgG are detectable in serum soon after onset
Hep A
- vaccine!
NOTE: detection of IgN anti-HAV is excellent test for dx acute Hep A
- partially dsDNA
- acute illnes usually subsides over 2-3 weeks, 5-10% chronic
- low-grade fever, enlarged and tender liver, jaundice
- assoc with polyarteritis nodosa
- parenteral, sexual, perinatal transmission
- endemic in sub-saharan Africa and SE Asia
- HBsAg-positive mothers may transmit HBV at delivery, risk of chronic infection in infant is 90%
- elevated aminotransferases early in course (higher than HAV infection)
- substantial risk for cirrhosis -> HCC
Hep B
- vaccine!