Types of Jaundice
Why is early-onset jaundice (<24 hours) always considered pathological, and what are the top 3 causes?
Physiological jaundice never occurs so early; main causes include hemolytic disease of the newborn (Rh/ABO), G6PD deficiency, and sepsis.
Why is unconjugated bilirubin neurotoxic, while conjugated bilirubin is not?
Unconjugated bilirubin is lipid-soluble, crosses the BBB, and deposits in basal ganglia; conjugated bilirubin is water-soluble and cannot penetrate neuronal tissue.
Name one nursing diagnoses of a baby with hyperbilirubinema.
fluid volume deficit related to increased insensible water loss and frequent loose stools, impaired tissue integrity related to loose stool due to phototherapy, risk for injury related to use of phototherapy, sensory-perceptual alternations related to neurologic damage secondary to kernicterus, and risk for altered parenting related to parenting a newborn with jaundice
Why does acidosis increase the risk of bilirubin encephalopathy?
Acidosis reduces bilirubin binding to albumin, increasing free unconjugated bilirubin available to cross the BBB.
What is the utility of transcutaneous bilirubinometry, and what are its limitations?
Non-invasive screening tool correlating with TSB; less reliable at higher bilirubin levels (>15 mg/dL), in dark-skinned infants, or under phototherapy.
How does phototherapy works?What wavelength range of light is most effective for phototherapy, and why?
It works by transforming the bilirubin into water soluble isomers that can be expelled without the liver conjugating the bilirubin.Blue-green light between 460–490 nm; it matches the absorption peak of bilirubin, maximizing photoisomerization and excretion.
What histopathological brain changes are seen in kernicterus?
Bilirubin deposition in basal ganglia, hippocampus, subthalamic nuclei, and brainstem nuclei with neuronal necrosis and gliosis.
How does the Bilirubin/Albumin ratio help guide management in severe hyperbilirubinemia?
It estimates the risk of bilirubin crossing the blood-brain barrier—when the ratio exceeds ~0.5 mg bilirubin per gram albumin, there is an increased risk of kernicterus, prompting aggressive treatment.
What is direct hyperbilirubinemia?
Direct Bilirubin more than 4 or 20% of the total
Explain why intensive phototherapy is preferred over conventional phototherapy in cases of extreme hyperbilirubinemia.
Intensive phototherapy delivers higher irradiance (≥30 µW/cm²/nm) to more effectively photoisomerize unconjugated bilirubin into water-soluble forms, reducing the need for exchange transfusion in severe cases.
During phototherapy, what is the rationale behind frequent feeding, and how does it help in reducing serum bilirubin?
Frequent feeding promotes intestinal motility and defecation, reducing enterohepatic circulation of bilirubin by eliminating bilirubin in stool, thus lowering serum bilirubin levels.
Why do preterm infants have a higher risk of bilirubin encephalopathy compared to term infants, even at lower bilirubin levels?
Immature blood-brain barrier, lower albumin binding capacity, and higher susceptibility of neuronal tissue to bilirubin toxicity.
Mutation in MRP2 gene → Impaired biliary excretion of conjugated bilirubin. Characterized by black liver pigmentation.
Dubin johnson syndrome
Inspissated Bile Syndrome (IBS)?
Inspissated Bile Syndrome (IBS) is a rare cause of neonatal cholestatic jaundice where bile in the bile ducts becomes thick, forming sludge that obstructs the flow of bile.
What is the role of Tin Mesoporphyrin in managing neonatal hyperbilirubinemia, and what is its mechanism of action?
Tin Mesoporphyrin (SnMP) competitively inhibits heme oxygenase, reducing the conversion of heme to biliverdin and thereby lowering unconjugated bilirubin production at the source
What safety checks must a nurse perform before starting exchange transfusion?
Cross-match compatibility, calcium preparation availability, double-volume blood calculation, monitoring equipment readiness, and aseptic catheter insertion site.
What is the importance of monitoring for hypocalcemia during exchange transfusion, and which clinical signs indicate severe hypocalcemia in neonates?
Citrate in donor blood chelates calcium, risking tetany, apnea, and cardiac arrhythmias. Clinical signs include jitteriness, carpopedal spasm, poor feeding, and bradycardia. Calcium gluconate must be available.
What is the diagnostic relevance of measuring end-tidal carbon monoxide corrected for hemoglobin (ETCOc) in neonates with jaundice?
ETCOc reflects bilirubin production via heme catabolism; elevated values indicate hemolysis as the underlying cause.