hepatology Flashcards
Direct hyperbilirubinemia in an infant: what is the cause and pathophysiology?
marker for cholestasis. usually caused by neonatal hepatitis or biliary atresia; other posibilities include CF, cholestasis from TPN, sepsis, coledochal cyst. direct hyperbilirubinemia is always pathologic in neonates. (direct bilirubin >15% t-bili)
Indirect hyperbilirubinemia in an infant: what is the most common cause and pathophysiology?
usually physiologic in nature- ie jaundice that usually occurs in the first week of life and resolves spontaneously without treatment. may be due to increased bilirubin load on hepatocytes and delayed activity of glucuronyl transferase
what is the ddx for indirect hyperbilirubinemia in a neonate?
- physiologic jaundice
- increased RBC load from bruiing (birth trauma, cephalohematoma)
- increased bilirubin from hemolysis (ABO-rh incompatibility, pyruvate kinase deficiency)
- breastfeeding jaundice or breast milk jaundice
- upper GI obstruction (increases enterohepatic recirculation)
- inborn errors of metabolism or inherited disorders of bilirubin uptake and conjugation (Gilbert’s disease, crigler-najjar)
- sepsis
(later: inspissated bile syndrone)
breastfeeding jaundice
- occurs in first week of life
- usually related to suboptimal milk intake
- causes weight loss, dehydration, retained stool, decreased bilirubin excretion
breastmilk jaundice
- after first week of life
- due to high levels of beta glucuronidase and lipase in breast milk
- highest in wks 2-3. lower levels may persist until wk 10
evaluation for indirect hyperbilirubinemia in an infant
CBC, retic count, smear. maybe sepsis eval
evaluation for direct hyperbilirubinemia in infant
hepatic ultrasound, serologies for viral hepatits, HIDA scans
complications of neonatal jaundice
kernicterus and bilirubin encephalopathy. indirect bilirubin can pass through BBB and cause irreversible damage, often in the basal ganglia and hippocampus. causes choreoathetoid cerebral palsy, hearing loss, opisthotonus (severe hyperextension), seizures
inspissated bile syndrome
associated with hemolysis or large hematoma. unconjugated hyperbili predominates early, but then conjugated hyperbili occurs due to increase in HCC function to meet demand
criggler niggar: types 1 and 2
type 1: AR, 100% of UDP-glucuronyl transferase is absent. kernicterus occurs almost universally
type 2: AD; 90% of enzyme activity is absent. kernicterus somewhat less likely
causes of cholestasis
- infection (sepsis, hepatitis, viral)
- metabolic issues (CF, hypothyroid, galactosemia)
- mechanical obstruction (biliary atresia or stricture
- hepatic obstruction (alagille)
- idiopathic
- alpha1 antitrypsin deficiency
- TPN disease
neonatal hepatitis: presentation, treatment
- most common cause of cholestasis in newborn
- jaundice and hepatomegaly in first week of life (hepatomegaly in 50%)
- FTT may occur
- usually self-limited course; tx is supportive but you may give ursodeoxycholic acid to enhace bile flow and reduce bile viscosity (may also give nutritional support)
biliary atresia: definition and epi
progressive fribrosclertic disease that affects the extrahepatic biliary tree. causes half of peds liver transplant
features of biliary atresia
- most patients present between 4-6 wks with jaundice, dark urine, and pale/acholic stools
- rest present earlier- often confused with physiologic jaundice
- T-bili moderately high
- rapid progression- bile duct obliteration and cirrhosis by 4 mo
- may also have HSM, ascites
polysplenia syndrome
bilobed lungs, abdominal heterotaxia, situs ambiguous, biliary atresia. present early and are more rapidly progressive
