RT Book, Section
A1 Barrie, Jamie
A1 Jivan, Kuntal
A2 Freeman, Brian S.
A2 Berger, Jeffrey S.
SR Print(0)
ID 1102567554
T1 Caudal Anesthesia
T2 Anesthesiology Core Review: Part One Basic Exam
YR 2014
FD 2014
PB McGraw-Hill Education
PP New York, NY
SN 9780071821377
LK accessanesthesiology.mhmedical.com/content.aspx?aid=1102567554
RD 2024/04/18
AB In  neonates  and  infants,  the  conus  medullaris  is  located  at  L3,  which  is  more  caudal  than  in  adults  (L1).  Because  of  the  difference  in  the  rates  of  growth  between  the  spinal  cord  and  the  bony  vertebral  column,  the  conus  medullaris  reaches  L1  at  approximately  1  year  of  age.  Thus,  lumbar  puncture  for  subarachnoid  block  in  neonates  and  infants  should  be  performed  at  L4-L5  or  L5-S1  so  as  not  to  injure  the  spinal  cord.  The  midline  approach  is  preferred  over  paramedian  because  the  vertebral  laminae  are  poorly  calcified  in  neonates  and  infants.The  sacrum  is  narrower  and  flatter  in  neonates.  This  difference  affects  the  approach  to  the  subarachnoid  space  from  the  caudal  canal.  It  is  much  more  direct  in  neonates  than  in  adults.  The  needle  must  not  be  advanced  deeply  in  neonates  because  dural  puncture  is  much  more  likely.The  distance  from  the  skin  to  the  subarachnoid  space  in  neonates  is  approximately  1.4  cm,  progressively  increasing  with  age.  The  ligamentum  flavum  is  much  thinner  and  less  dense  in  children  than  adults,  which  makes  it  more  difficult  to  detect  engagement  of  the  epidural  needle  and  results  in  unintended  dural  puncture.Cerebrospinal  fluid  (CSF)  volume  per  percentage  of  body  weight  is  greater  in  infants  than  in  adults.  This  may  account  for  the  comparatively  larger  doses  of  local  anesthetics  required  for  surgical  anesthesia  with  subarachnoid  block.A  caudal  block  may  be  contraindicated  in  the  presence  of  a  deep  sacral  dimple  because  this  may  indicate  the  presence  of  spina  bifida  occulta,  thus  greatly  increasing  the  probability  of  dural  puncture.