RT Book, Section
A1 Gomella, Tricia Lacy
A1 Eyal, Fabien G.
A1 Bany-Mohammed, Fayez
SR Print(0)
ID 1168356796
T1 Hyperbilirubinemia: Conjugated, On Call
T2 Gomella's Neonatology: Management, Procedures, On-Call Problems, Diseases, and Drugs, 8e
YR 2020
FD 2020
PB McGraw-Hill Education
PP New York, NY
SN 9781259644818
LK accesspediatrics.mhmedical.com/content.aspx?aid=1168356796
RD 2024/04/18
AB An  infant’s  direct  (conjugated)  serum  bilirubin  level  is  elevated  at  3  mg/dL.  Conjugated  bilirubin  is  the  fraction  of  bilirubin  that  is  conjugated  with  glucuronic  acid  in  the  liver  to  form  bilirubin  diglucuronide.  It  is  a  biochemical  marker  of  cholestasis.  Neonatal  cholestasis  is  conjugated  hyperbilirubinemia  in  the  newborn  period  and  is  an  accumulation  of  bile  substances  in  the  liver.  It  is  secondary  to  decreased  bile  secretion  from  the  liver  to  the  duodenum  and  usually  signifies  an  underlying  hepatobiliary  or  metabolic  dysfunction.  Cholestasis  can  be  extrahepatic/obstructive  (most  commonly  biliary  atresia,  other  causes  include  choledochal/biliary  cyst,  inspissated  bile  syndrome,  obstructive  tumors,  gallstones)  or  intrahepatic/nonobstructive  (idiopathic,  infectious,  metabolic/genetic,  autoimmune,  or  toxic).  This  chapter  incorporates  recommendations  from  the  North  American  Society  for  Pediatric  Gastroenterology,  Hepatology,  and  Nutrition  (NASPGHAN),  the  European  Society  for  Pediatric  Gastroenterology,  Hepatology,  and  Nutrition  (ESPGHAN),  and  the  American  Academy  of  Pediatrics  (AAP)  on  the  management  of  hyperbilirubinemia  in  the  newborn  infant  35  or  more  weeks  of  gestation.  NASPGHANdefines  an  abnormal  direct  bilirubin  as  >1  mg/dL.  The  AAPdefines  an  abnormal  direct  bilirubin  as  >1  mg/dL  if  the  total  serum  bilirubin  (TSB)  level  is  ≤5  mg/dL.  If  the  TSB  level  is  >5  mg/dL,  a  direct  bilirubin  >20%  of  the  TSB  is  abnormal.  The  majority  of  prolonged  physiologic  jaundice  is  secondary  to  breast  milk  jaundice,  but  it  is  important  not  to  misdiagnose  cholestasis  as  physiologic  jaundice  because  this  will  delay  the  early  diagnosis  that  is  essential  for  treatment.  Conjugated  hyperbilirubinemia  is  never  normal  or  physiologic  and  indicates  hepatobiliary  dysfunction.  It  occurs  in  1  in  every  2500  term  infants,  and  common  causes  in  the  newborn  infant  are  biliary  atresia  (25%–40%),  monogenic  disorders  (25%),  and  multifactorial  or  unknown  etiologies.  The  more  common  causes  in  premature  infants  are  prolonged  parenteral  nutrition  and  sepsis.  Timely  diagnosis  is  critical  for  successful  treatment  and  optimal  prognosis,  in  particular  for  biliary  atresia.  Kasai  hepatic  portoenterostomy  should  be  done  as  soon  as  possible  to  establish  bile  flow  and  is  best  performed  within  the  first  60  days  of  life  (approximately  70%  with  bile  flow  vs  90  days).  See  also  Chapter  98  for  additional  discussion  on  conjugated  hyperbilirubinemia  management.