Pediatrics Exam

Question 1

True or false: all newborns experience some type of jaundice

Answer 1

True

Question 2

Jaundice occurs when serum bilirubin exceeds:

Answer 2

Albumin binding capacity

Question 3

__________________ can pass the blood brain barrier.

Answer 3

Unbound (free) bilirubin

Question 4

Bilirubin is a neurotoxin that can cause:

Answer 4

• kills brain cells
  1. Bilirubin encephalopathy
  2. Kernicterus

Question 5

What is kernicterus?

Answer 5

Permanent syndrome that can occur from increased levels of unbound bilirubin the brain. Brain damage that may include problems with hearing and vision

Question 6

How to assess jaundice?

Answer 6

Examine child every 8-12 hours
Blanch skin (use thumbs to pull skin apart)
Cephalocaudal progression (head to toe)
Serum bilirubin at 24 hours of life
Serum bilirubin at 36 hours of life

Question 7

Associated signs/symptoms with neonatal jaundice (on physical exam)

Answer 7

Petechiae
Pallor
Cephalohematoma
Bruising
Hepatosplenomegaly
Weight loss
Dehydration
Sepsis

Question 8

Metabolism of bilirubin

Answer 8

1. RBC broken down (heme)
2. Heme broken down to bilirubin
3. Bilirubin to liver
4. Bilirubin paired to albumin and sent to intestine via bile
5. Bilirubin converted to urobilinogen
6. Urobilinogen converted to either stercobilin (excreted in stool) or urobilin (excreted in urine)

Newborns differ at 3 different steps

Question 9

Causes of indirect bilirubinemia (3 reasons)

Answer 9

1. RBC catabolism, heme release –> increased production of bilirubin
2. UGT1A1 < 1% functional birth –> decreased clearance of bilirubin
3. No intestinal bacteria to break down bilirubin –> increased enterohepatic circulation of bilirubin

Question 10

What does UGT1A1 do?

Answer 10

Converts unconjugated bilirubin to conjugated bilirubin

Question 11

Due to ethnic variation in __________, total bilirubin peaks a little bit higher and later in ___________ newborns

Answer 11

UGT1A1

East Asia

Question 12

Definition of physiologic jaundice

Answer 12

Jaundice that is not visible until after 24 hours of age

Due to elevated indirect (unconjugated) bilirubin

Question 13

Tx of direct hyperbilirubinemia:

Answer 13

Surgery before 2 months old to avoid liver transplant

Question 14

Causes of direct hyperbilirubinemia

Answer 14

Cholestasis

Question 15

Disorders leading to increased production (hemolysis) (<24 hrs), leading to indirect bilirubinemia

Answer 15

Hemolytic Disease of the Fetus and Newborn
Heritable red blood cell membrane defects
Red blood cell enzyme defects
Sepsis
Polycythemia
Cephalohematoma
Macrosomnia

Question 16

Disorders leading to decreased clearance, leading to indirect bilirubinemia

Answer 16

Crigler-Najjar Syndrome Type 1 and 2
Gilbert Syndrome
Infant of a diabetic mother
Congenital hypothyroidism
Galactosemia

Question 17

Disorders leading to increased enterohepatic circulation, leading to indirect bilirubinemia

Answer 17

Breast milk jaundice
Breastfeeding jaundice
Intestinal obstruction or ileus

Question 18

Breast milk jaundice

Answer 18

Due to unknown substance in breastmilk
Presents after 1st week of life
Resolves by 12 weeks
Continue breastfeeding

Question 19

Breastfeeding jaundice

Answer 19

Deficient breastfeeding
Presents during first week of life
Consider temporary supplementation with banked human milk or formula

Question 20

Symptoms of direct hyperbilirubinemia (cholestasis)

Answer 20

Jaundice, pale stools, dark urine

Question 21

Direct hyperbilirubinemia (cholestasis) is defined as:

Answer 21

Direct bilirubin > 1.0 mg/dL if TsB < 5.0 mg/dL

Direct bilirubin > 20% of TsB if TsB > 5.0 mg/dL

Question 22

Disorders that can cause direct hyperbilirubinemia (cholestasis):

Answer 22

Hepatitis
Endocrinopathy
Inborn errors of metabolism
Alpha-1 antitrypsin deficiency
Total parenteral nutrition
Sepsis
Biliary atresia

Question 23

How do you calculate indirect bilirubin?

Answer 23

Subtract direct bilirubin from total bilirubin

Question 24

Principles of phototherapy treatment

Answer 24

Blue-green wavelength
Isomerization of bilirubin to water soluble form (then excreted via urine)
Diaper and eye protection only
Triple lights

Question 25

Direct antiglobulin test (Coomb’s Test)

Answer 25

Looks for antibodies attached to RBCs

Can help determine hemolytic anemia

Question 26

What are some principles of HDFN?

Answer 26

Mother is Type O
Child is not
Mother passes antibodies through placenta to child, which cause hemolytic state, can lead to indirect hyperbilirubinemia

Question 27

ABO incompatibility occurs in ___% of all pregnancies, but leads to hemolysis in only ____%

Answer 27

15%

0.6%

Question 28

Treatment if HDFN is suspected:

Answer 28

Initiate phototherapy first

Obtain CBC and peripheral smear

Question 29

How long to continue phototherapy?

Answer 29

Check TsB 2-4 hours after starting phototherapy.
Then check 8-12 hours later.
Discontinue when TsB has fallen below starting level
Consider checking a rebound TsB is 4 hours

Question 30

For rebound TsB after discontinuation of phototherapy, a quick rate of rise is greater than ________ per hour

Answer 30

0.2 mg/dL

Question 31

What is the most common cause of pediatric liver transplant?

Answer 31

Biliary atresia –> leads to direct hyperbilirubinemia (cholestasis)