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Neonatal Jaundice. Ruben Bromiker Department of Neonatology Shaare Zedek Medical Center. Physiologic Jaundice. Healthy infants up to 12mg% in 3rd day; in premature, 5th day. No hemolysis or bleedings No underlying metabolic disease. Mechanism. Production: Volemia,
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Neonatal Jaundice Ruben Bromiker Department of Neonatology Shaare Zedek Medical Center
Physiologic Jaundice • Healthy infants • up to 12mg% in 3rd day; in premature, 5th day. • No hemolysis or bleedings • No underlying metabolic disease
Mechanism • Production: • Volemia, • RBC span (90 days) • Ineffective erythropoyesis • Turnover of non Hb heme proteins
Mechanism • Enterohepatic recirculation: • Glucuronidase • Bilirubin monoglucuronide • Intestinal bacteria • Intestinal motility and stooling
Mechanism • Bilirubin Uptake : ligandin • Conjugation : UDPG-T activity • Hepatic excretion of bilirubin
Neonatal Hyperbilirubinemia • Visible jaundice: • Adults: >2mg% • Newborns: >6mg • Up to 50% of all newborns may develop jaundice
Source of Bilirubin • Metabolism of heme. 6-10 mg/kg/day. (adults 3-4mg/kg/day) • 1gr Hemoglobine produces 34mg of bilirubin • 75%: from old RBCs released from RES • 25%: from ineffective erythropoyesis, myoglobine, cytochromes, catalase, peroxidase.
Metabolism Heme Oxygenase + O2 Heme Biliverdin + CO + Fe Biliverdin reductase Indirect (unconjugated) bilirubin Binds to albumin in plasma
Indirect bilirubin Conjugation • Liver Uptake (binds to ligandin) Endoplasmic reticullum • Bilirubin Mono and diconjugated bilirubin UDPG-T Liver Excretion Gut • Elimination • Enterohepatic recirculation • Urobilinoids • Stool • Beta glucuronidase • Bacteria
Jaundice: Physical examination • Blanch skin with a finger Jaundice • Significant when appears at palms or below knees. • Transcutaneous bilirubinometer • Bruising, cephalohematoma, others. • Organomegaly
Dermal Zones of Jaundice After leaving RES bilirubin binds to albumin, initially with low affinity, thus bilirubin precipitates in the proximal parts of the body before it does it distally. So jaundice appears first proximally, and later distally.
Jaundice: Laboratory • Total serum bilirubin • Blood type, Rh, Coombs infant and mother • Smear (morphology and reticulocytes) • Hematocrit
Jaundice: Laboratory • Antibody identification • Direct bilirubin: • When more than 2 weeks old or signs of cholestasis • If prolonged: • LFT, TORCH, sepsis work-up, metabolic, thyroid • G6PD
Non Physiologic Jaundice • Onset at < 24 hs • Bilirubin over levels for phototherapy • Bilirubin rise > 0.5 mg%/hr • Signs of underlying illness • Vomiting, lethargy, poor feeding, weight • Age > 8 days in term or 15 days in premature
Non Physiologic Jaundice: Anamnesis • Familial: • G6PD, spherocytosis, metabolic, enzymes. • Siblings: • Immune, breast milk. • Pregnancy: • Infections, drugs, diabetes. • Delivery: • Trauma, cord clumping, asphyxia.
Bilirubin toxicity: Cerebral Penetration: As free indirect bilirubin or bound when disrupted BBB • Disrupted BB barrier • Hyperosmolarity • Anoxia • Hypercarbia • Prematurity
Bilirubin toxicity: Factors Unbound indirect bilirubin • Albumin concentration • 1gr albumin binds 8.5mg bilirubin • Displacement from albumin site • FFA • Drugs: Sulfonamides • Correction of acidosis
Bilirubin toxicity: Kernicterus Neuronal injury + yellow staining of brain incidence in hemolytic disease (especially RH) • Basal ganglia • Cranial nerve and cerebral nuclei • Hippocampus • Anterior horn of spinal cord Localization
Bilirubin toxicity: Chronic complications • Athetosis • Sensorial deafness • Limited upward gaze • Intellectual deficits • Dental dysplasia
Bilirubin toxicity • Healthy full-term infants: • Abnormality in ABR • Hypotony: reverses with bilirubin levels • Very rarely kernicterus • Low birth weight infants: • Damage most probably due to accompanying factors than to high bilirubin.
Breast Feeding Jaundice • Bilirubin after 4 days of age. Healthy infants • Resolves after holding breast milk for 1-2 days • Presentation • Early: 2-4 days of age • Late: after 4 days of age
Breast Feeding Jaundice: Mechanism • Interference with hepatic conjugation • Beta glucuronidase in milk • Reduced bacterial colonization of gut • Caloric intake intestinal motility recirculation • FFA suggested to reduce bilirubin metabolism
Isoimmune hemolytic disease of the newborn • Rh , or minor types (Kell, Duffy, E, C,c) • 15% of people are Rh- • Coombs + • Maternal sensitization d/t previous pregnancy, transfusion, amniocentesis, abortion
IHDN: Pregnancy Management • Coombs titers >1/16 or previous history of severe disease Amniocentesis for optical density • High levels, and clinical signs of hydrops Intrauterine transfusion • Intraperitoneal, intravascular or intracardiac • Repeated transfusions switched fetal blood type
IHDN: Newborn Management • Check immediately after birth • Hematocrit • Bilirubin • Blood type • 50% will only need phototherapy • 24% will be anemic and cord bilirubin >4mg% exchange transfusion
IHDN: Prevention Anti D (Rh) immune globulin indications • At 28 weeks • within 72 hours since birth. • Procedures or suspected transplacental hemorrhage.
ABO hemolytic disease of the newborn • 15% of pregnancies mother O infant A or B • 20% will develop significant jaundice • 10% will need phototherapy. • Presentation: • Early jaundice (<24hs of life) • Many times Combs -, but there are antibodies • Blood smear: spherocytes
Treatment: Phototherapy • Bilirubin best absorbs light at 450 hm. • The best is to provide it with blue light. • White range: 380-700 hm also adequate. • Irradiation generates photochemical reaction in the extravascular space of the skin • A higher illuminated area increases effectiveness
Treatment: Phototherapy Mechanism • Photoisomerization: • Natural Isomer 4Z,15Z 4Z,15E hydrosoluble blood biliar secretion (unconjugated) • Slow excretion and fast reisomerization reabsorbed. • Photooxydation: Small polar products. Slow
Treatment: Phototherapy mechanism • Structural isomerization: • Ciclization to lumirubin (irreversible) bile and urine • Fast excretion not reabsorption. • Related to dose of phototherapy (intensity of light)
Treatment: Phototherapy mechanism Main Pathway Bilirubin Lumirubin
Phototherapy: Technique • Fluorescents ,spots or biliblankets • More than 5mw/cm2 at 425-475hm • Naked , covering eyes • Increase fluids 10-20% • Check bilirubin every 12-24hs • Stop: 13±1mg% in term, 10±1mg% in preterm • Check 12-24hs later for rebound
Phototherapy: Side effects • Increased water loss • Diarrhea • Retinal damage • Bronze baby, tanning • Mutations in DNA? shield scrotum • Disturb of mother-infant interaction.
Exchange transfusion: Technique • Irradiated PC < 7 days + FFP. Warmed • Double of blood volume. • Open incubator, monitors • Route • UV: push-pull, over > 1hr • Artery-vein: Isovolumetric
Exchange transfusion: Complications • Hypocalcemia-hypomagnesemia (CPD) • Hypoglycemia (monitor Dx after exchange) • Acid base disturbances • Hyperkalemia • Cardiovascular: • Embolizations, arrhythmia, perforation, arrest.
Exchange transfusion: Complications • Bleeding • Thrombocytopenia, loss of factors. • Infections • Hemolysis • GVHD • Other • Fever, hypothermia, NEC?
Neonatal Jaundice:Other treatments • Phenobarbital: conjugation • Oral agar: enterohepatic circulation • Metalloporphyrins: inhibit bilirubin production. • Competitors of heme oxygenase • IVIGg: inhibits hemolysis. • Binds to FC receptor of reticuloendothelial cells
Management of Hyperbilirubinemia in the Healthy Term Newborn*
Jaundice Diagnostic approach to neonatal jaundice Measure Bilirubin Non physiologic Blood type, Rh, Coombs Hematocrit, Smear, Reticulocytes Increased direct bili Increased indirect bili Coombs + Sepsis TORCH Biliary Atresia Cholestasis Inspissated Bi Hepatitis CF Tyrosinosis Galactosemia Coombs - Hematocrit ABO Rh minor group Polycytemia N or¯Hematocrit RC shape Normal Bleedings Enterohepatic Metabolic Drugs Other Abnormal Specific and non specific Abnormalities