Neonatal Hyperbilirubinemia

Question 1

Approximately what % of all term newborns and most preterm infants develop clinical jaundice

Answer 1

85%.

Question 2

The term Severe Neonatal Jaundice. …?

Answer 2

cute bilirubin encephalopathy (ABE), kernicterus, ET, or jaundice-related death

Question 3

How much bilirubin will produce by the normal newborn …?

Answer 3

A normal newborn produces 6 to 10 mg of bilirubin/kg/day, greater than the adult production of 3 to 4 mg/kg/day.

Question 4

One gram of hemoglobin produces how much of bilirubin…?

Answer 4

34 mg

Question 5

Etiology for Displacement of bilirubin from albumin..?

Answer 5

acidosis,
by drugs, such as ceftriaxone, or
by free fatty acids (FFAs) at high molar ratios of FFA:albumin may increase bilirubin toxicity.

Question 6

Gilbert’s syndrome etiology …..?

Answer 6

Polymorphisms in the UGT1A1 gene due to differences in the number of thymine–adenine repeats in the promotor gene diminish the expression of the UGT1A1 enzyme and result in increased TB levels (Gilbert’s syndrome)

Question 7

UGT activity in newborn as compared to adults …?

Answer 7

In term infants at 7 days of age, UGT activity is approximately 1% that of adults and

reaches adult levels only by 3 months of age.

Question 8

HYPERBILIRUBINEMIA definition ..?

Answer 8

It is defined as a TB >95th percentile (on the hour-specific Bhutani nomogram)

Question 9

severe hyperbilirubinemia and require evaluation …..?

Answer 9

1. Onset of jaundice before 24 hours of age
2. An elevation of TB that requires phototherapy
3. Rate of rise in total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) level of >0.2 mg/dL/hour
4. Associated signs of illness such as lethargy, poor feeding, and temperature instability
5. Jaundice persisting after 14 days in a term infant, high-colored urine, and pale stools

Question 10

the most common cause of hyperbilirubinemia …?

Answer 10

Hemolytic disease

Question 11

Crigler–Najjar syndrome due to

Answer 11

either absent UGT activity (type I) or reduced UGT activity (type II) results in severe hyperbilirubinemia.

Question 12

the most common inherited disorder of bilirubin glucuronidation..?

Answer 12

Gilbert’s syndrome

Question 13

Gilbert’s syndrome genetics ..?

Answer 13

Gilbert’s syndrome results from a mutation in the promoter region of the UGT1A1 gene, reducing the production of UGT

Question 14

When Gilbert’s syndrome will present ..?

Answer 14

Although the Gilbert genotype alone is not associated with increased hyperbilirubinemia, severe hyperbilirubinemia can result when an affected newborn also has increased bilirubin production or increased enterohepatic circulation

Question 15

Breast milk jaundice …?

Answer 15

occurs in about 2.4% of all infants.

Typically, it begins after the first 3 to 5 postnatal days, peaks within 2 weeks of age, and,

if breastfeeding is continued, gradually returns to normal levels over 3 to 12 weeks.

Question 16

Mechanisms of bilirubin reduction by phototherapy…?

Answer 16

1. The main mechanism is structural isomerization by light that irreversibly converts bilirubin to lumirubin, a more soluble substance that can be excreted into bile and urine without conjugation.
2. Photoisomerization rapidly converts about 15% of the 4Z, 15Z bilirubin isomer to the less toxic 4Z, 15E form
3. Photo-oxidation is a slow process that converts bilirubin to small polar products that are excreted in the urine and is the least important mechanism of bilirubin elimination

Question 17

the most effective are characteristics of phototherapy units …?

Answer 17

1. Light emission in the blue-green spectrum (460 to 490 nm), which includes the region (460 nm) where bilirubin most strongly absorbs light
2. Irradiance of at least 30 μW/cm2/nm
3. As close to the baby as possible (older recommendation of 45 cm should not be practiced)
4. Illumination of maximal body surface area
5. Shown to decrease TB during the first 4 to 6 hours of exposure

Question 18

Bronze baby” syndrome

Answer 18

Bronze baby” syndrome, a dark bronze discoloration of the skin thought to be related to impaired excretion of photoproducts of bile pigment, may occur with phototherapy in infants with direct hyperbilirubinemia (cholestatic jaundice) and usually resolves gradually within a few weeks after phototherapy is discontinued

Question 19

Intravenous immunoglobulin (IVIG)

Answer 19

Intravenous immunoglobulin (IVIG) has been used in infants with hemolytic disease caused by Rh or ABO incompatibility when TB continues to rise despite continuous intensive phototherapy or is within 2 or 3 mg/dL of the threshold recommended for ET

Question 20

Immediately after a double volume ET (about 160 to 180 mL/kg), TB values are typically…?

Answer 20

half the value prior to the procedure

Question 21

ET procedure replaces approximately WHAT PERCENTAGE of the circulating RBCs.

Answer 21

85%

Question 22

Neurologic manifestations of bilirubin toxicity early phase..?

Answer 22

Signs are subtle and may include lethargy, hypotonia, highpitched cry, and poor suck.

Question 23

Intermediate phase …?

Answer 23

hypertonia of extensor muscles (rigidity, opisthotonus, and retrocollis), oculogyric crisis, irritability, fever, and seizures. Some infants die in this phase. All infants who survive this phase are likely to develop chronic bilirubin encephalopathy (clinical diagnosis of kernicterus)

Question 24

Advanced phase…?

Answer 24

Signs include pronounced opisthotonus and retrocollis, cry that can be weak or shrill, apnea, seizures, and coma. Affected infants die from intractable seizures or respiratory failure

Question 25

BIND score

Answer 25

It assigns a score of 1, 2, or 3 to mild, moderate, or severe abnormalities, respectively, in an infant’s mental status, muscle tone, and cry pattern.

A total score of 1 to 3 indicates mild ABE but is indistinguishable from other causes unless ancillary investigations are done.

Scores of 4 to 6 and 7 to 9 indicate moderate and severe ABE, respectively.

Question 26

Kernicterus…?

Answer 26

Kernicterus refers to the chronic and permanent sequelae of bilirubin toxicity that develop during the first year of age

Question 27

The signs of kernicterus are as follows:…?

Answer 27

a. Choreoathetoid cerebral palsy with neuromotor impairments

b. Sensorineural hearing loss (auditory neuropathy), characterized by abnormal brainstem auditory evoked response with normal otoacoustic emission testing

c. Limitation of upward gaze

d. Dental enamel dysplasia

Question 28

Indications for DVET at birth in infants with Rh isoimmunization include:…?

Answer 28

1. Cord bilirubin is 5 mg/dL or more, OR
2. Cord Hb is 10 g/dL or less

Question 29

Indications of partial exchange transfusion…?

Answer 29

At birth, if a baby shows signs of hydrops or cardiac decompensation in presence of low PCV (<35%), partial exchange transfusion with 50 mL/kg of packed cells should be done to restore oxygen carrying capacity of blood, before doing DVET

Question 30

Type and volume of blood for exchange transfusion in

1. Rh isoimmunization -

Answer 30

Rh negative and blood group ‘O’ or that of baby Suspended in AB plasma and cross matched with baby’s and mother’s blood

Question 31

2. ABO incompatibility-

Answer 31

Rh compatible and blood group ‘O’ (Not that of baby) suspended in AB plasma cross matched with baby’s and mother’s blood

Question 32

3. Other conditions (G6PD deficiency, non-hemolytic, other isoimmune hemolytic jaundice

Answer 32

Baby’s group and Rh type cross matched with baby’s and mother’s blood

Question 33

Volume of blood…?

Answer 33

Twice the blood volume of baby (total volume: 160 to 180 mL/kg)

Question 34

To prepare blood for DVET,

Answer 34

mix two-thirds of packed cells and one-third of plasma

Question 35

Exchange transfusion …?

Answer 35

The actual exchange should be performed slowly in aliquots of 5–10 cc/kg body weight

each withdrawal-infusion cycle approximating 3-minute duration

Using this approach, a double volume exchange should take approximately 1.5 ± 0.5 hours and avoids deleterious hemodynamic changes