RT Book, Section
A1 Malcolm, William F.
SR Print(0)
ID 1105545124
T1 Intestinal Failure
T2 Beyond the NICU: Comprehensive Care of the High-Risk Infant
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 978-0-07-174858-2
LK accesspediatrics.mhmedical.com/content.aspx?aid=1105545124
RD 2024/04/23
AB DefinitionIntestinal  failure  refers  to  the  inability  of  a  patient  to  sustain  oneself  via  the  enteral  route.Often,  the  loss  of  intestinal  length  due  to  surgical  resection  is  referred  to  as  either  short  gut  syndrome  or  short  bowel  syndrome,  although  these  terms  exclude  forms  of  intestinal  failure  in  which  intestinal  length  is  normal  but  may  not  allow  for  proper  absorption  of  nutrients.Primary  causes  for  intestinal  failure  in  neonates  includeNecrotizing  enterocolitis:  A  multifactorial  inflammatory  condition  of  the  GI  tract  that  has  a  large  spectrum  of  severity  and  the  most  severe  form  results  in  full-thickness  bowel  necrosis.Intestinal  atresia:  Failure  of  part  of  the  intestinal  tract  to  completely  form,  causing  an  obstruction.Gastroschisis:  Full-thickness,  typically  right-sided,  paraum-  bilical  abdominal  wall  defect  and  primarily  has  the  intestines  and  stomach  protruding  through  the  defect  in  the  amniotic  fluid.Omphalocele:  Anterior  abdominal  wall  defect  at  the  base  of  the  umbilical  cord  with  herniation  of  intra-abdominal  contents  within  sac  made  of  the  layers  of  the  umbilical  cord.Midgut  volvulus:  A  condition  in  which  the  intestines  become  twisted  due  to  malrotation  during  fetal  development.IncidenceNEC  is  the  most  common  cause  of  intestinal  failure  in  infants  and  is  diagnosed  in  roughly  one  to  three  per  1000  live  births  and  the  incidence  increases  to  approximately  10%  in  infants  of  very  low  birthweight  (<1500  g).PathophysiologyThe  exact  etiology  of  NEC  is  not  known.Multiple  processes  can  lead  to  an  ischemic  insult  to  the  gastrointestinal  mucosa.Prematurity  and  low  birthweight  appear  to  be  risk  factors  perhaps  due  to  immaturity  of  the  immune  system  and  underdevelopment  of  the  GI  mucosal  barrier.Risk  factorsIn  neonates,  surgical  resection  necessitated  by  either  congenital  or  acquired  diseases  represent  the  most  common  causes  of  intestinal  failure,  with  necrotizing  enterocolitis,  gastroschisis,  atresias,  and  midgut  volvulus  representing  the  most  common  causes  of  intestinal  failure.However,  functional  disorders  of  motility,  such  as  long-segment  Hirschsprung  disease,  and  enterocyte  disorders,  such  as  intestinal  epithelial  dysplasia,  may  also  be  encountered  in  this  age  group.Whatever  the  cause,  the  ultimate  goal  of  treatment  is  to  allow  for  normal  growth  while  allowing  for  intestinal  rehabilitation  in  the  hopes  that  the  patient  will  eventually  be  able  to  sustain  himself/herself  via  the  enteral  route.Clinical  presentationThe  clinical  signs  of  NEC  are  nonspecific  and  overlap  with  neonatal  sepsis.The  earliest  signs  include  lethargy,  abdominal  distention,  and  vomiting.More  advanced  disease  may  present  with  gross  blood  in  the  stool,  vital  sign  instability,  abdominal  wall  erythema,  peritonitis.DiagnosisThe  diagnosis  or  NEC  is  often  suspected  when  the  triad  of  neutropenia,  thrombocytopenia,  and  acidosis  is  identified.In  addition,  plasma  C-reactive  protein  and  stool  reducing  substances  may  aid  in  the  diagnosis;  however,  there  are  no  specific  lab  studies  that  confirm  the  diagnosis  of  NEC.Radiographic  imaging  with  two-view  abdominal  radiographs  will  virtually  always  reveal  generalized  intestinal  dilation  consistent  with  ileus.  Pneumatosis  intestinalis  is  considered  pathopneumonic,  but  may  be  only  transiently  evident  even  in  severe  forms.  Advanced  cases  may  demonstrate  free  air  associated  with  perforation  or  the  presence  of  portal  venous  gas.Ultrasonography  has  been  used  to  assist  with  identification  of  ascites,  may  help  to  assess  segments  of  bowel  for  thinning  or  decreased  perfusion,  may  demonstrate  portal  venous  gas.The  Bell  classification  divides  the  disease  into  three  ...