Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
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 |
