03.12 Jaundice in Children

Question 1

Also known as icterus

Yellow discoloration of the skin and sclerae due to excess bilirubin in the blood

Answer 1

Jaundice

Question 2

Increased levels of conjugated bilirubin

Answer 2

Direct hyperbilirubinemia

Question 3

Increased levels of unconjugated bilirubin

Answer 3

Indirect hyperbilirubinemia

Question 4

Primary site of erythropoiesis

Answer 4

Bone marrow

Question 5

Hemoglobin is then phagocytosed by _____, and is split into globin and heme

Answer 5

Macrophages (RES)

Question 6

In the third step, heme is converted into ____ through the action of ____

Answer 6

Biliverdin

Heme oxygenase

Question 7

The formed biliverdin is rapidly reduced to free ___ through the aciton of ____

Answer 7

Bilirubin

Biliverdin reductase

Question 8

Site of conjugation for bilirubin

Answer 8

Liver

Question 9

Released bilirubin is conjugated to ____ through the action of ____

Answer 9

Glucoronic acid

Glucoronyltransferase

Question 10

The conjugated form of bilirubin has the following characteristics

Answer 10

Greenish
Water soluble
Readily excreted

Question 11

The conjugated bilirubin is then secreted through ____ in the _____

Answer 11

Ampulla of Vater

2nd segment of the duodenum

Question 12

The conjugated bilirubin is acted upon by bacteria in the ____ , which causes the removal of glucuronic acid through ___, and converting the conjugated bilirubin into ____

Answer 12

Terminal ileum and proximal colon
Hydrolysis
Urobilinogen

Question 13

Colorless

Water soluble

Answer 13

Urobilinogen

Question 14

90% of the urobilinogen is further oxidized by bacteria forming ____, which is oxidized to ____ that contributes to the brown color of the feces

Answer 14

Stercobilinogen

Stercobilin

Question 15

Etiology of direct hyperbilirubinemia

Answer 15

Decreased excretion by the damaged hepatic parenchymal cells

Disease of the biliary tract

Question 16

Often signifies a serious hepatic or systemic illness

Answer 16

Conjugated direct hyperbilirubinemia

Question 17

Etiologies of indirect hyperbilirubinemia

Answer 17

Increased load of bilirubin to be metabolized by the liver (hemolytic anemia, polycythemia, shortened red cell life, increased enterohepatic circulation, infection)
Damaged or reduced activity of the transferase enzyme (genetic deficiency, hypoxia, infection, thyroid deficiency)
Factors that competes for or blocks the transferase enzymes (drugs, etc)
Factors that lead to absence or decreased amounts of enzyme or to reduction of bilirubin uptake by the liver cells (genetic defect, prematurity

Question 18

Also known as icterus neonatorum

Occurs in 60% of term infants and 80% of preterm infants

Answer 18

Physiologic jaundice

Question 19

Most common reason of bilirubin accumulation in physiologic jaundice is a ______

Answer 19

Breakdown of fetal RBC

Question 20

Visible manifestations of jaundice in icterus neonatorum appears at the _____ when serum bilirubin levels are _____

Answer 20

2nd-4th day of life

5-6 mg/dL

Question 21

Under normal circumstances, the level of indirect bilirubin in umbilical cord serum is _____ and rises at a rate of ____

Answer 21

1-3 mg/dL

<5 mg/dL/day

Question 22

Hyperbilirubinemia (___ mg/dL) in 13% of breastfed infants in the ____ due to _____ with _____ is referred to as ____

Answer 22

12
1st week of life
Decreased milk intake
Dehydration or reduced caloric intake
Breastfeeding jaundice

Question 23

Mild form of dehydration in 1st week of life due to decreased milk intake
May be due to the shift towards non-exclusive breastfeeding

Answer 23

Breastfeeding jaundice

Question 24

Hyperbilirubinemia (___ mg/dL) after the ___ in 2% of BF infants is referred to as ____

Answer 24

10-30
7th day of life
Breastmilk jaundice

Question 25

Some milk has a ____ that causes the breastmilk jaundice

Answer 25

Glucoronidase

Question 26

Warning signs for pathological jaundice

Answer 26

Appears int he first 24 hours of life Serum bilirubin rising at a rate faster than 5mg/dL Serum bilirubin > 12 mg/dL Jaundice persists after 10-14 days of life Direct-reacting bilirubin >2 mg/dL

Question 27

Types of jaundice

Answer 27

Physiologic | Pathologic

Question 28

Causes of increased direct bilirubin

Answer 28

``` Sepsis Intrauterine infection (toxoplasmosis, CMV, rubella, herpes, syphilis) Severe hemolytic disease Choledochal cyst Cystic fibrosis Galactosemia Alpha1-antitrypsin deficiency Tyrosinemia ```

Question 29

Looks for Abs that may stick to your red blood cells and cause RBCs to die early

Answer 29

Coombs test

Question 30

Most common cause of indirect hyperbilirubinemia in the infant is _____

Answer 30

Isoimmunization

Question 31

Production of antibodies against constituents of tissues of another individual of the same species

Answer 31

Isoimmunization

Question 32

An elevated HgB may indicate ____ due to:

Answer 32

``` Polycythemia Due to: -twin transfusion -maternal-fetal transfusion -delayed cord clamping -small for gestational age infant ```

Question 33

Salient features of neonatal jaundice

Answer 33

``` Maternal history Birth history Parental blood type Onset Clinical course Interval history Vital signs Organomegaly Maturity Feeding history Nutritional history ```

Question 34

Transcutaneous measurements of jaundice in face, mid-abdomen and soles

Answer 34

5 mg/dL 15 20

Question 35

Jaundice is bright yellow or orange in ___ hyperbilirubinemia, greenish to mud yellow in ___

Answer 35

Indirect | Direct

Question 36

Complication of hyperbilirubinemia Bilirubin encephalopathy Neurologic syndrome resulting from the deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei

Answer 36

Kernictus

Question 37

Treatment of hyperbilirubinemia

Answer 37

Phototherapy | Exchange transfusion

Question 38

Skin absorbs blue light and thorugh photoisomerization converts the toxic ubilirubin into the unconjugated configurational isomer that may be excreted without conjugated

Answer 38

Phototherapy