【医学课件】新生儿黄疸（英文版）.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Neonatal Jaundice,Case:History(1),Baby Liu,49 hrs old,was noted to be Jaundiced for about 30hrs(from 19hrs of life).,Mother was a 26 years old G1 P0,she went into spontaneous labour at 40+6 wks,no premature rupture of membrane.,APGARS were 9/9 at 1/5 minutes respectfully.Birth weight was 3260g.,Baby,s clinical examination post delivery was normal and baby roomed in with mother and breast feeding was attempted.Baby passed stool on two occasions,and the color was yellow.,History(2),There was no family history of jaundice,anemia,splenectomy,early gallbladder disease or liver disease.,Mother was healthy during pregnancy.,The physical examination,On arrival to the hospital baby was nondysmorphic and his clinical exam was normal except he looked pale.,Respiratory:No concerns baby remained well in room air.,Cardiovascular:No concerns,Abdomen:No abnormality detected.Baby fed well.,CNS:Baby Liu was neurologically appropriate for age.He had good suck,moro and grasp reflex.There was no concern with his tone.There was no cephalohematoma.,Haematology:His CBC on admission was Hb 108,WBC 12.5,platelets of 326,Ret 9%,CRP 2mg/L,Purpose of discussion,Further clinical test,Diagnosis,Therapy,Question,Was this baby,“,physiologic jaundice,”,or,“,nonphysiologic jaundice,”,?,Physiologic Jaundice,The serum UCB level of most newborn infants rises to 2 mg/dL in the first week of life.This level usually rises in full-term infants to a peak of 6 to 8 mg/dL by 3 days of age and then falls.A rise to 12 mg/dL is in the physiologic range.,In premature infants,the peak may be 10 to 12 mg/dL on the fifth day of life,possibly rising 15 mg/dL without any specific abnormality of bilirubin metabolism.,Nonphysiologic Jaundice,Onset of jaundice before 24 hours of age.,Any elevation of serum bilirubin that requires phototherapy(see next page).,A rise in serum bilirubin levels of,0.,5,mg/dL/hour or,5,mg/dL/,day.,Direct bilirubin concentration 1.5-,2mg/d L,Jaundice has withdrawed but reproduced again.,Clinical jaundice persisting for more than 2 weeks in a,full-term infant,Guidelines for phototherapy,“,Onset of jaundice before 24 hours of age.,”,He was nonphysiologic jaundice.,Review:,Source of bilirubin,Bilirubin is derived from the breakdown of heme-containing proteins in the reticuloendothelial system.,1.,The major heme-containing protein is,red blood cell(RBC)hemoglobin.,Hemoglobin released from senescent RBCs in the reticuloendothelial system is the source of 75%of all bilirubin production.,2.,The other 25%of bilirubin is called,early-labeled bilirubin.,It is derived from hemoglobin released by ineffective erythropoiesis in the bone marrow,from other heme-containing proteins in tissues(e.g.,myoglobin,cytochromes,catalase,and peroxidase),and from free heme.,Review:,Bilirubin metabolism(1),The heme ring from heme-containing proteins is oxidized in reticuloendothelial cells to,biliverdin,by the microsomal enzyme heme oxygenase.,Biliverdin is then reduced to bilirubin by the enzyme,biliverdin reductase.,Review:,Bilirubin metabolism(2),1.Transport.,Bilirubin is nonpolar,insoluble in water,and is transported to liver cells bound to serum,albumin.,2.Uptake.,Nonpolar,fat-soluble bilirubin(dissociated from albumin)crosses the hepatocyte plasma membrane and is bound mainly to cytoplasmic,ligandin,(Y protein)for transport to the smooth endoplasmic reticulum.,Review:,Bilirubin metabolism(3),3.Conjugation.,Unconjugated(indirect)bilirubin(UCB)is converted to water-soluble conjugated(direct)bilirubin(CB)in the smooth endoplasmic reticulum by,uridine diphosphate glucuronyl-transferase(UDPG-T).,4.Excretion.,CB in the biliary tree enters the gastrointestinal(GI)tract and is then eliminated from the body in the stool,which contains large amounts of bilirubin.CB is not normally resorbed from the bowel unless it is converted back to UCB by the intestinal enzyme,-glucuronidase.,Resorption of bilirubin from the GI tract and delivery back to the liver for reconjugation is called,enterohepatic circulation.,Causes of Unconjugated Hyperbilirubinemia(1),A.Excessive production of bilirubin(hemolytic disease of newborn),1.Blood group heterospcificity(incompatibility),a.Rh isoimmunization,b.ABO incompatibility,c.Minor blood group incompatibility,2.Red blood cell enzyme abnormalities,a.Glucose-6-phosphate dehydrogenase deficiency,b.Pyruvate kinase deficiency,3.Sepsis,4.Red blood cell membrane defects,a.Hereditary spherocytosis,b.Elliptocytosis,c.Poikilocytosis,5.Extravascular blood,6.Polycythemia,Causes of Unconjugated Hyperbilirubinemia(2),B.Impaired conjugation or excretion,1.Hormonal deficiency,a.Hypothyroidism,b.Hypopituitarism,2.Disorders of bilirubin metabolism,a.Crigler-Najjar syndrome type I,b.Crigler-Najjar syndrome type II(Arias disease),c.Gilbert disease,d.Lucey-Driscoll syndrome,3.Enhanced enterohepatic circulation,a.Intestinal obstruction,pyloric stenosis,b.Ileus,meconium plugging,cystic fibrosis,Causes of Conjugated Hy。