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Jaundice occurs by:
Deposition of the pigment bilirubin
What is it called when pigment bilirubin builds up in the brain, causing damage?
What is an ultimate adverse effect of kernicterus in infantcy?
athetoid CP (uncontrolled movement of face, body, amrs, and legs)
What is the correct terminology for scleral icterus?
Conjunctival icterus (which is the membrane covering the sclera)
Which form of bilirubin is water solubable?
What form of bilirubin is lipid-soluble?
Which type of bilirubin builds up in the brain, leading to kernicterus?
Unconjugated because it is lipid-soluable and able to cross the B-B-B.
Where is unconjugated bilirubin converted to bilirubin?
How is bilirubin produced? (2 processes)
- Heme catabolism
- 1. breakdown of RBC
- 2. breakdown of other heme proteins (10%)
What enzyme breaks down the heme?
Enzyme heme oxygenase (HO), located in the spleen and liver
Bilirubin is the byproduct of what?
Biliverdin (results from breakdown of heme)--> converts to bilirubin with biliverdin reductase
Discuss the process of unconjugated bilirubin.
Biliverdin--> unconjugated bilirubin--> binds w/ albumin & transported to liver--> dissociates and enters hepatocyte--> conjugated into H20-soluable--> secreted into bile--> eliminated in the intestines
T or F. Conjugated bilirubin can be excreted both renally and hepatically.
What enzyme can unconjugate bilirubin to be reabsorbed into circulation?
What are 4 ways that conjugated bilirubin can build up?
- 1. Decrease excretion
- 2. Liver dysfunction
- 3. gall bladder disorder
- 4. portal system dysfunction
What 3 things can effect the amount of free bilirubin in the body?
- 1. Binding capacity of albumin
- 2. affinity of tissue
- 3. pH of blood
What are 5 causes of unconjugated/indirect bilirubin buildup?
- 1. hemolysis condition
- 2. decreased hepatic uptake
- 3. decreased conjucation
- 4. impaired hepatic secretion
- 5. biliary obstruction
What are 4 clinical results of Indirect Hyperbilirubenemia?
- 1. Physiologic jaundice
- 2. Ciglar-Najjar syndrome
- 3. Breast milk jaundice
- 4. jaundice 1st day of life
What are the 3 main causes of Indirect Hyperbilirubinemia?
- 1. Overproduction
- 2. Impaired hepatic uptake
- 3. Decreased conjugation
What are the 2 major causes of Direct Hyperbilirubinemia?
- 1. Defect in excretion of bilirubin from hepatocyte into the bile
- 2. mechanical obstruction of the bile
What are 4 common causes of Direct Hyperbilirubinemia?
- 1. Infection (CMV) & sepsis
- 2. Neonatal hepatitis
- 3. cholestasis
- 4. bilirubin displacing drugs (sulfa)
What is a symptom of biliary atresia and what type of Hyperbilirubinemia is it?
- -Direct Hyperbilirubinemia
- -Dark urine & gray-white stool
What is the 2nd most come cause of hyperbilirubinemia?
**Increased bilirubin production (breakdown of RBCs secondary to hemolysis/nonhemolysis)
What are some causes of hyperbilirubinemia when associated with NON-hemolysis?
- -Physiological jaundice
- -Breast milk jaundice
- -infants of DM moms
- -Gilbert's dx
- -Decreased caloric intake, pyloric stenosis, endocrine issues
What is the most common hereditary cause of increased bilirubin?
Gilbert's disease (benign)
What some examples of hemolytic cause of excess bilirubin?
- -ABO, Rh incompatibility
- -Thalassemia, G6PD
- -congenital infections
Which ethnic groups have an increased risk of hyperbilirubinemia?
-Asian, Native American, Mediterranean
What are some causes in labor that increased risk factor for excess bilirubin?
- -oxytocin use in labor
- -instrumentation use in delivery (forceps, vaccum)
List risk factors for hyperbilirubinemia?
- -Asian, Native American, Med
- -labor causes
- -preemies (35-37wks)
- -Sibling w/ jaundice
- -cephalhematoma, unknown bleed
What percent of babies born has some level of clinical jaundice with STB >5?
What level STB can result in encephalopathy (kernicterus)?
STB > 20
What ethnic group has an STB that peaks around 72-96hrs? Which group peaks to max around 1 week?
- 72-96hr--> european/african
- 1 week--> native american, east asia
What is the goal in primary care?
Differentiate between physiologic jaundice from pathologic
What is a red flag for jaundice in newborns?
Jaundice at 1st day of life! (>5mg)
When does jaundice normally occur and resolve in infants?
Occurs b/w 2-5 DOL, lasts until day 8(in term) or day 14(in preemies)
What STB is considered normal peak on DOL 3?
STB (12mg/dl), preterm may be 15mg on DOL 5
Which is usually associated with a higher STB, breastfed or formula fed?
When is breastfeeding jaundice most common?
When parents feeding <8x/24hrs or having difficulty establishing a feeding pattern
Breast milk jaundice is an increase in unconjugated bilirubin or conjugated bilirubin?
- Breast milk jaundice--> unconjugated bili
- -present after DOL 5 and can persist for months
What STB is associated with clinical jaundice of face, body/naval, extremety, & hands/feet jaundice?
- Face--> ~4-8
- Naval--> ~5-8
- Extremety ~8-12
- Hands/feet ~ >15
What clinical jaundice should be evaluated with serum level?
If jaundice below the level of the chest or worsening--> measure
T or F. If the blanched skin is yellow, it is jaundice.
Jaundice below the chest requires which labs?
- -Serum direct/indirect bilirubin
- -CBC w/ smear
- -retic count
- -blood type
- -End tidal CO
- -UA/blood cultures if septic
When should a workup for metabolic or genetic disease or cholestasis/biliary atresia be initiated?
If DIRECT/conjugated bili is elevated
Which urine color is associated with pre-hepatic jaundice?
- Normal urine color
- (dark color--> hepatic/post-hepatic jaundice)
What are 5 RED FLAGs to support pathologic jaundice?
- 1. Clinical jaundice w/in 24hrs of life
- 2. STB >95th for age in hours
- 3. STB ⇑ by >0.05mg/hr
- 4. Direct bili fraction >1.5mg
- 5. Clinical jaundice persisting >2wk in full term
When should an early f/u for jaundice be performed? (5)
- -discharged <48-72hr
- -poor feeding
- -ABO incompatibility
- -clinically jaundice
What constitutes an infant that is "low risk" for bili?
Low risk--> >38wks and w/out risk factors
What are the values to start phototherapy at 24, 48, & 72hrs for "low risk" infants?
- Phototherapy for low risk
- 24--> >12
- 48--> >15
- 72--> >18
What infants are considered "mod risk" for elevated bili?
>38wk with risk factors, 35-38 wks without risk factors
What levels should phototherapy be started for "mod risk" infants?
- 24--> >10
- 48--> >13
- 72--> >15
What infants are considered "high risk" for elevated bili?
35-37+5wk with risk factors
What levels should phototherapy be started for "high risk" infants?
- 24--> 8
- 48--> 11
- 72--> 13.5
What safety measure should be taken for infants undergoing phototherapy?
When should exchange transfusion be considered in hyperbili babies?
STB >20 for infants w/ hemolysis & wt >2000g
When should exchange transfusion for elevated bili in babies < 2000g?
Exchange transfusion should be initiated at <20 if babies <2000g
Where in the brain does excess bili deposit?
At what STB level is Kernicterus most often associated?
STB > 20-25mg (depends on gestational age)
What are clinical signs of kernicterus? (early & late)
- Early--> lethary, hypotonia, irritability, poor feeding, high pitched cry, emesis
- Late--> fever, bulging fontanel, seizure, hypertonicity
What are 4 side effects of kernicterus in kids that survive?
- 1. Athetoid CP
- 2. nerve deafness
- 3. mental retardation
- 4. discoloration of teeth