1、Neonatal JaundiceDezhi Mu MD/PhDDepartment of Pediatrics, West China Second University Hospital, Sichuan UniversityIntroduction Jaundice is quite common (5mg/dl). Full term infants: at least 50% Preterm infants: over 80% Elevated blood bilirubin levels: 97%Introduction continued When?in the first we
2、ek of life Where?skin , mucosa and white of eye How many?blood bilirubin concentrations is5-7mg/dl. Introduction continued Producing Excreting Why Jaundice occurred?Bilirubin Metabolism:1. RBC: Heme bilirubin (UCB) 2. Blood: carried by bound to albumin3. Liver: uptaken : Y protein, Z proteinconjugat
3、ed: UDPGTexcreted： to the biliary system 4. Intestine: stercobilins -glucuronidase enterohepaticcirculationThe metabolic characteristics of bilirubin in newborns: 1. Bilirubin production 8.8mg/Kg/d in newborns 3.8mg/Kg/d in adults 2. Bilirubin-albumin complex formationa. preterm infant;b. acidosis 3
4、. Bilirubin metabolism of hepatocyte a. Hepatic uptake of bilirubin b. Bilirubin conjugation: UDPGT (uridine diphosphate glucoronyl transferase)c. Defective bilirubin excretion ability to bile system4. Enterohepatic circulation The metabolic characteristics of bilirubin continuedBilirubin toxicity1. Conjugated bilirubin water-soluble 2. Unconjugated bilirubinlipid-solublebilirubin-encephalopathy （ kernicterus）
