Low Risk Neonatal Nurse Exam Neonatal Jaundice & Hyperbilirubinemia 2 — Questions and Answers
Question 1: What defines 'physiologic jaundice' in a full-term newborn?
- Jaundice appearing within the first 24 hours of life
- Jaundice appearing after 24 hours, peaking around days 3–5, and resolving by 2 weeks of age (Correct answer)
- Any jaundice requiring phototherapy
- Jaundice caused by ABO or Rh blood group incompatibility
Correct answer: Jaundice appearing after 24 hours, peaking around days 3–5, and resolving by 2 weeks of age
Physiologic jaundice follows a predictable pattern: onset after 24 hours, bilirubin peak around day 3–5, and resolution by 2 weeks in term infants due to normal immaturity of hepatic conjugation.
Question 2: What does a positive direct antiglobulin test (DAT/Coombs) indicate in a jaundiced newborn?
- The infant has elevated unconjugated bilirubin from hepatic immaturity
- Maternal antibodies are attached to the infant's red blood cells, indicating immune-mediated hemolysis (Correct answer)
- The infant has G6PD deficiency
- Sepsis is the cause of the jaundice
Correct answer: Maternal antibodies are attached to the infant's red blood cells, indicating immune-mediated hemolysis
A positive DAT means maternal IgG antibodies have crossed the placenta and coated the infant's red blood cells, causing immune-mediated hemolytic disease and elevated bilirubin.
Question 3: How does breast milk jaundice differ from breastfeeding (insufficient intake) jaundice?
- Breast milk jaundice occurs in the first week due to inadequate milk intake; breastfeeding jaundice occurs after week 2
- Breastfeeding jaundice occurs in the first week from inadequate intake; breast milk jaundice appears after day 5–7 and may persist several weeks from substances in mature breast milk (Correct answer)
- Both conditions occur at the same time and have identical causes
- Breast milk jaundice requires immediate formula substitution; breastfeeding jaundice resolves without intervention
Correct answer: Breastfeeding jaundice occurs in the first week from inadequate intake; breast milk jaundice appears after day 5–7 and may persist several weeks from substances in mature breast milk
Breastfeeding (starvation) jaundice peaks in the first week from inadequate caloric intake; breast milk jaundice is a distinct entity peaking after day 5–7 from beta-glucuronidase and other factors in mature milk that increase enterohepatic circulation.
Question 4: How is bilirubin normally processed and eliminated in the newborn?
- Filtered by the kidneys and excreted directly into urine in unconjugated form
- Conjugated by glucuronyl transferase in the liver, excreted in bile, and eliminated in stool (Correct answer)
- Bound to hemoglobin and recycled by the spleen
- Converted to urobilinogen in the bloodstream and filtered by the lungs
Correct answer: Conjugated by glucuronyl transferase in the liver, excreted in bile, and eliminated in stool
The liver conjugates unconjugated (fat-soluble) bilirubin using glucuronyl transferase to form a water-soluble form excreted in bile and passed in stool; immaturity of this process causes physiologic jaundice.
Question 5: Which essential nursing intervention must be maintained throughout phototherapy treatment?
- Wrapping the infant snugly in blankets to maintain temperature
- Applying protective eye shields and keeping them in place during all light exposure (Correct answer)
- Positioning the infant prone to maximize skin surface exposure
- Restricting oral fluids to prevent bilirubin reabsorption in the gut
Correct answer: Applying protective eye shields and keeping them in place during all light exposure
Phototherapy light can cause retinal damage; eye shields must be applied and checked frequently to ensure they remain properly positioned and covering both eyes throughout treatment.
Question 6: A newborn's total serum bilirubin is rising faster than 0.5 mg/dL per hour. This rate of rise is most consistent with:
- Normal physiologic jaundice in a breastfed infant
- Breast milk jaundice beginning in the second week
- Hemolytic disease requiring urgent evaluation and possible intensive phototherapy or exchange transfusion (Correct answer)
- Benign neonatal polycythemia resolving spontaneously
Correct answer: Hemolytic disease requiring urgent evaluation and possible intensive phototherapy or exchange transfusion
A bilirubin rise exceeding 0.5 mg/dL/hour indicates accelerated hemolysis, not normal bilirubin production, and requires immediate workup for hemolytic disease and potentially intensive treatment.
Question 7: What is the enterohepatic recirculation of bilirubin, and why is it clinically significant in neonates?
- The process by which phototherapy metabolizes bilirubin in the skin, reducing the need for hepatic conjugation
- The reabsorption of unconjugated bilirubin from the intestine back into the bloodstream, which is enhanced in neonates due to beta-glucuronidase activity and delayed stooling (Correct answer)
- The circulation of conjugated bilirubin through the bile duct system
- The binding of bilirubin to albumin in hepatic sinusoids
Correct answer: The reabsorption of unconjugated bilirubin from the intestine back into the bloodstream, which is enhanced in neonates due to beta-glucuronidase activity and delayed stooling
Neonates have high intestinal beta-glucuronidase that deconjugates bilirubin in the gut, allowing it to be reabsorbed; delayed meconium passage and infrequent feedings worsen this cycle.
Low Risk Neonatal Nurse Exam Neonatal Jaundice & Hyperbilirubinemia 2
What defines 'physiologic jaundice' in a full-term newborn?