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35 Cards in this Set

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At what levels of serum bilirubin does jaundice occur?
5mg/dL in neonates
2mg/dL in children & adolescents
Which type of hyperbilirubinemia is always pathologic? Direct or indirect?
direct
What is bilirubin?
a bile pigment formed from the degradation of heme derived from RBC destruction and ineffective erythropoiesis
Define conjugated hyperbilirubinemia.
direct fraction in blood exceeds 15% of total or 2mg/dL
How does unconjugated bilirubin usually travel in the blood?
bound to albumin
What is a complication of unconjugated hyperbilirubinemia?
free bilirubin crosses BBB and causes kernicterus
What is kernicterus?
yellow staining of basal ganglia and hippocampus, causing widespread cerebral dysfunction:
- lethargy & irritability
- hypotonia
- opisthotonos
- seizures
- mental retardation
- cerebral palsy
- hearing loss
What is opisthotonos?
head thrown back, back is arched and heels kick back
What is "physiologic jaundice"?
unconjugated hyperbilirubinemia due to:
- increased RBC volume
- lower RBC survival time
- increased enterohepatic circulation
- defective hepatic bilirubin uptake
- UDP-glucuronyl-transferase activity
- defective bilirubin secretion
When does physiologic jaundice begin? What is the common course?
after first 24hrs of life
- peak of 12 to 15 mg/dL at day 3
- returns to normal levels by end of 1st week
What are risk factors for physiologic jaundice?
- prematurity
- maternal diabetes
- Asian or Native American ancestry
What is mxn of breast milk jaundice? How is the presentation different than physiologic jaundice?
unknown

infant's peak bilirubin level is higher and lasts longer than physiologic jaundice
When should infants with hyperbilirubinemia be evaluated?
- hyperbilirubinemia in first 24hrs of life
- increase in serum bilirubin greater than 5mg/dL/day
- jaundiced with other risk factors
- prolonged jaundice (+1wk in term; +2wks in premie)
- conjugated bilirubinemia
What is the broad DDX in unconjugated hyperbilirubinemia?
- physiologic jaundice
- hemolytic process
What is the DDX for immune problems in unconjugated hyperbilirubinemia?
- ABO/Rh incompatibility
- erythroblastosis fetalis
- drug rxn (penicillin, sulfonamides, oxytocin)
What is the DDX for red cell defects in conjugated hyperbilir.?
- structural: spherocytosis, elliptocytosis
- hemoglobinopathy: sickle cell, alpha-thalassemia
- enzyme deficiency: G6PD or pyrivate kinase deficiency
What presentation can be common in DIC, polycythemia and swallowed maternal blood?
jaundice
What causes of extravascular blood loss can lead to unconjugated jaundice?
- bruising from birth trauma: petechiae, cephalohematoma
- hemorrhage: pulmonary, cerebral
What disorders of bilirubin metabolism can lead to unconjugated hyperbilirub.?
- Gilbert's syndrome
- Crigler-Najjar syndrome
- Lucey-Driscol syndrome
What causes of increased enterohepatic circulation lead to unconjugated jaundice?
- intestinal obstruction: pyloric stenosis, duodenal stenosis or atresia, annular pancreas
- Hirschsprung's disease
- meconium ileus and/or meconium plug syndrome
- drug-induced paralytic ileus (magnesium)
What drug leads to paralytic ileus and thus unconjugated hyperbilirubinemia?
magnesium
What endocrine complications lead to unconjugated hyperbilirubin.?
- hypothyroidism
- infants of diabetic mothers
- hypopituitarism
Can bacterial sepsis cause jaundice?
yes!
What are important Q's in the history of a pt. with jaundice?
- family history of RBC structural defects, hemoglobinopathies or enzyme deficiencies?
- mom have previous child with ABO incompatibility?
- family hx of genetic or chromosomal disorders?
- congenital infection in birth hx?
What is a change in stool and urine color associated with jaundice?
turns to grey and urine darkens
How does neonatal jaundice progress in the body?
cephalopedal: from head to toe
If jaundice has reached umbilicus, roughly what is the level?

If palms and soles are involved, what is it then?
10+ mg/dL

15+ mg/dL
What are the first tests that need to be ordered in jaundice?
- CBC w/ peripheral blood smear and retic count
- maternal and infant blood types
- Coombs' test (direct and indirect)
- fractions of conjugated vs. unconjugated hyperbilirubin.
What is the goal in treating unconjugated hyperbilirub.?
avoid kernicterus and sublethal bilirubin encephalopathy
What causes of extrahepatic obstruction lead to conjugated hyperbilirubinemia?
- biliary atresia
- choledoclithiasis
- choledochal cyst
- common duct stenosis
- inspissated bile syndrome (CF)
- extrinsic bile duct compression
- pancreatitis
What causes of persistent intrahepatic cholestasis leads to conjugated hyperbilirub.?
- paucity of intrahepatic ducts
- benign recurrent intrahepatic cholestasis
- arteriohepatic dysplasia
What are causes of acquired intrahepatic cholestasis?
- neonatal hepatitis: bacterial sepsis, congenital infections, hep A B C, varicella, EBV, echovirus, coxsackie virus, TB, leptospirosis, amoebiasis
- drug-induced cholestasis
- TPN cholestasis
- cirrhosis
- drug or metal toxicity
- neoplasms: hepatoblastoma, secondary liver metastases
What are disorders of bilirubin metabolism causing direct hyperbilir.?
- Dubin-Johnson syndrome
- Rotor's syndrome
What disorders of carbohydrate metabolism can cause direct hyperbiliru.?

What aa metabolic disorders?

What lipid metabolism disorders?
- galactosemia, fructosemia

- tyrosinemia, hypermethioninemia

- Niemann-Pick disease, Gaucher's disease
What chromosomal disorders can cause direct hyperbilirubinemia?

What metabolic liver disease causes it?
trisomy 18 and 21

Wilson's disease, alpha-1-antitrypsin disease