Hyperbilirubinemia Neonatal Hyperbilirubinemia

Jaundice Yellow discoloration of skin due to elevated serum bilirubin level > 5mg/dl in neonates > 2 mg/dl in older children

Bilirubin Produced in the reticuloendothelial system as the end product of heme catabolism Isomers: Z (cis) – lipid-soluble E (trans) – water-soluble Sources: hemoglobin (75%), myoglobin, catalase, cytochromes, cyclooxygenase, guanyl cyclase

Hyperbilirubinemia in Neonates Predisposing factors –Increased RBC mass –Decreased red cell survival (70-90 days) –Immature hepatic function –Decreased hepatic blood flow –Breastfeeding

Pathophysiology hemoglobin biliverdin binds with ligandin intracellularly Cis-bilirubin heme oxygenase + albumin unconjugated bilirubin Bilirubin + glucuronic acid urobilinogen UDPGT B-glucuronidase enters hepatocyte reabsorbed in small intestine excreted

Kernicterus Sequelae due to non-albumin bound indirect bilirubin depositing on the basal ganglia at mg/dl S/Sx: poor suck, hypotonia, extensor hypertonia, decreased sensorium, fever Also results to cerebral palsy with athetosis, oculomotor damage & high frequency hearing loss 10% mortality, 70% long-term morbidity

Kramer’s Classification (Cephalopedal Progression) ZoneJaundiced AreasSerum Bilirubin (mg/dl) IHead/Neck6-8 IIUpper trunk9-12 IILower trunk/Thigh12-14 IVArms/Legs/Elbows/Knees15-18 VHands/Feet>18

Neonatal Jaundice FactorsPHYSIOLOGICPATHOLOGIC Onset>24 hour of life 1 week Duration<2 week>1 week (term) >2 weeks (preterm) Total Bilirubin<12mg/dl (term) <15mg/dl (preterm) >12mg/dl (term) >15mg/dl (preterm) Increase Rate of TB >5mg/dl/day Direct Bilirubin >2mg/dl or 15% of TB Signs & Symptoms Vomiting, lethargy, poor suck, apnea

Physiologic Jaundice FactorBREASTFEEDINGBREASTMILK Onset3 rd -4 th day of life4 th -6 th day of life Duration<1-2 weekPeaks at 2 nd -3 rd week <10-12 weeks PathophysiologyDecreased milk intake increases enterohepatic circulation Due to a compound in breastmilk which competitively inhibits glucuronyl transferase

Diagnostics Total bilirubin, direct bilirubin, indirect bilirubin Fetal and maternal blood typing Coomb’s test Hemoglobin, Hematocrit Reticulocyte count RBC morphology Urinalysis Liver UTZ

Management Adequate hydration and nutrition Phototherapy Exchange transfusion –indicated if phototherapy is inadequate or if at high risk of developing kernicterus

Phototherapy Recommended range 5-10 mcw/nm/cm2 Photoisomerization – isomer is converted to less toxic, polar isomer; excreted in bile Structural Isomerization – conversion to lumirubin, which is rapidly excreted, reaction is irreversible and not reabsorbed Photooxidation – conversion to small, polar products, excreted in urine

Phototherapy Indications: –Prophylactic. In preterm infants or those with hemolytic disease to prevent a significant rapid rise in serum bilirubin –Therapeutic. In late-preterm and full- term infants to reduce excessive bilirubin levels and avoid development of kernicterus

Bhutani Chart

Bhutani Chart Summary

Phototherapy ends when… TSB became low at levels: 13+/- 0.7mg/dl (term), 10.7+/-1.2mg/dl (preterm) No risk factors for reaching toxic levels of bilirubin Direct bilirubin level is increasing Note: check total bilirubin 12-24hours after phototherapy

Side Effects of Phototherapy Increased insensible water loss (add 10% to TFR while on phototherapy) Watery diarrhea Hypocalcemia in preterm Retinal damage Skin tanning Bronze-baby syndrome Mutations (shield genitalia)

Fluid Requirement Add 10% more to the TFR because there is increased insensible water loss due to phototherapy

Nutritional Requirement Early feeding since patient is large for gestational age LGA neonates are prone to hypoglycemia Hyperbilirubinemia result also from inadequate feeding