1.Physiological neonatal jaundice Most common cause of jaundice 1Unconjugated hyperbilirubinemiawww.medicinemcq.com

2. Neonatal Bilirubin Metabolism Major source of bilirubin 2Breakdown of hemeEach gram of hemoglobin yields 34 mg of bilirubinwww.medicinemcq.com 3. www.medicinemcq.com3 4. www.medicinemcq.com4 5. www.medicinemcq.com5 6. www.medicinemcq.com6 7. www.medicinemcq.com7 8. www.medicinemcq.com8 9. www.medicinemcq.com9 10. www.medicinemcq.com10 11. www.medicinemcq.com11 12. www.medicinemcq.com12 13. www.medicinemcq.com13 14. Bilirubin level is normal at birth 1.8 to 2.8 mg/dL Bilirubin produced by the fetus Cleared by the placenta 14Eliminated by the maternal liverwww.medicinemcq.com 15. Neonatal liver Must conjugate bilirubin and excrete it 15Immediately after birthwww.medicinemcq.com 16. Glucuronyl transferase (UDPGT) Conjugates bilirubin in the liver Water-soluble 16Excreted into bilewww.medicinemcq.com 17. Neonatal liver Incompletely developed at birth Low levels of UDPGT at birth 17Impaired conjugationwww.medicinemcq.com 18. Enterohepatic circulation Unconjugated bilirubin pass into the gut 18Alternative excretory pathwaysEnterohepatic circulation of unconjugated bilirubinwww.medicinemcq.com 19. Most neonates Mildunconjugated hyperbilirubinemia 192 to 5 days after birthwww.medicinemcq.com 20. Physiologic jaundice Factors contributing Low UDPGT activity Relatively high red cell mass Increased enterohepatic circulation of bilirubin in the first days of life Absence of intestinal flora Slow intestinal motility 20www.medicinemcq.com 21. Physiologic jaundice Factors contributing Low UDPGT activity Relatively high red cell mass Increased enterohepatic circulation of bilirubin in the first days of life Absence of intestinal flora Slow intestinal motility 21www.medicinemcq.com 22. Physiologic jaundice Factors contributing Low UDPGT activity Relatively high red cell mass Increased enterohepatic circulation of bilirubin in the first days of life Absence of intestinal flora Slow intestinal motility 22www.medicinemcq.com 23. Physiological Jaundice Features Appears after 24 hours of age Total bilirubin 23Rises by < 5 mg/dL per daywww.medicinemcq.com 24. Jaundice at birth Pathological 24Hemolytic disease Infectionwww.medicinemcq.com 25. Peak levels < 15 mg/dL Normal serum bilirubin Within 2 weeksMay last for up to 4 weeks Premature infants Exclusively breast fed babies 25www.medicinemcq.com 26. Premature babies Liver immaturity is more severe 26Higher levels of unconjugated hyperbilirubinemia developwww.medicinemcq.com 27. Neurotoxicity Unconjugated bilirubin can cross the blood brain barrier 27Binds to the phospholipids (gangliosides) of neuronal plasma membranes causing injurywww.medicinemcq.com 28. Risk of neurotoxicity Albumin-bound unconjugated bilirubin Neurotoxicity 28Cannot cross the BBB When the plasma level exceeds that which can be tightly bound by albumin i.e., > 25 mg/dlwww.medicinemcq.com 29. ACUTE BILIRUBIN ENCEPHALOPATHY Lethargy, poor feeding Irritability, high-pitched cry Arching of the neck (retrocollis) and trunk (opisthotonos) Apnea, seizures, coma (late) 29www.medicinemcq.com 30. Kernicterus Chronic brain injury due to hyperbilirubinemia Staining of basal ganglia and brainstem nuclei 30www.medicinemcq.com 31. www.medicinemcq.com31 32. Kernicterus Extrapyramidal movement disorder (choreoathetoid cerebral palsy) Limitation of upward gaze Deafness Dysplasia of the enamel of the deciduous teeth 32www.medicinemcq.com 33. Conditions that can exaggerate physiologic Jaundice 1. 2. 3. 4. 5.33Diabetes in mother Polycythemia in infant Delayed cord clamping Cephalhematoma Intraventricular hemorrhagewww.medicinemcq.com 34. Conditions that can exaggerate physiologic Jaundice 6.7. 8. 9. 10.34Hypothyroidism (decreased UDPglucoronyl transferase activity) Congenital infections (decrease hepatic excretion of bilirubin) Hypoxia Congenital heart disease (decrease hepatic perfusion) Unfed babies (Increased enterohepatic circulation)www.medicinemcq.com 35. When to investigate neonatal jaundice? 35Occurrence in the first 24 hours of life Rate of increase > 5 mg/dL in 24 hours Total bilirubin levels > 12 mg/dL in full-term (> 10 to 14 mg/dL/24 hours in preterm infants) Hyperbilirubinemia continues after the second week of life Conjugated bilirubin levels > 2 mg/dL Dark urine or pale stool Failure of phototherapy to reduce the bilirubin Excess weight loss Neurologic signs Family history of hemolysis or hepatosplenomegaly www.medicinemcq.com 36. TREATMENT Self-limiting 36No treatment requiredwww.medicinemcq.com 37. Follow up 37Ensure that bilirubin levels decreasewww.medicinemcq.com 38. Phototherapy Reduce the level of unconjugated bilirubin If the bilirubin level remains high or increases 38www.medicinemcq.com 39. Phototherapy Converts bilirubin into photoisomers Soluble 39Can be excreted in bile without conjugationwww.medicinemcq.com 40. Light of wavelength 425475 nm Blue-green spectrum Absorbed by unconjugated bilirubin in the skin Convert it to a water-soluble stereoisomer 40Can be excreted in bile without conjugationwww.medicinemcq.com 41. www.medicinemcq.com41