NNP Hematology and Hyperbilirubinemia

Question 1

Which enzyme is responsible for converting heme to biliverdin in the catabolism of hemoglobin?

Accepted Answer

Heme oxygenase

Answer

Heme oxygenase cleaves the heme ring to produce biliverdin, carbon monoxide, and free iron, which is the first step in bilirubin production.

Question 2

A term neonate develops jaundice at 18 hours of age. Which of the following is the MOST likely cause?

Accepted Answer

ABO incompatibility hemolytic disease

Answer

Jaundice appearing within the first 24 hours of life is pathologic and most commonly caused by hemolytic disease such as ABO incompatibility.

Question 3

At what gestational age does fetal hemoglobin (HbF) begin to be replaced by adult hemoglobin (HbA)?

Accepted Answer

After 34–36 weeks gestation

Answer

The switch from HbF to HbA production begins at approximately 34–36 weeks gestation and continues postnatally over the first 6 months of life.

Question 4

Which of the following best describes physiologic jaundice in a term neonate?

Accepted Answer

Onset after 24 hours, peak by day 3–4, resolves by day 14

Answer

Physiologic jaundice in term neonates typically appears after 24 hours, peaks on days 3–4, and resolves by day 14, driven by increased bilirubin production and immature conjugation.

Question 5

A 3-day-old breastfed neonate has a total serum bilirubin (TSB) of 18 mg/dL. The mother reports the infant is nursing 8–10 times per day with adequate wet diapers. What is the MOST appropriate next step?

Accepted Answer

Begin phototherapy based on hour-specific nomogram

Answer

Management of neonatal hyperbilirubinemia should be guided by the AAP hour-specific nomogram, which determines phototherapy thresholds based on age in hours and risk factors.

Neonatal Nurse Practitioner Exam Practice Test

Neonatal Nurse Practitioner Exam Practice Test

NNP Hematology and Hyperbilirubinemia