RT Book, Section
A1 Freeman, Brian S.
A2 Freeman, Brian S.
A2 Berger, Jeffrey S.
SR Print(0)
ID 1102567575
T1 Epidural Test Dose
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=1102567575
RD 2024/04/16
AB A  catheter  positioned  properly  in  the  epidural  space  can  provide  excellent  surgical  anesthesia,  postoperative  analgesia,  and  labor  analgesia.  Inadvertent  placement  of  the  catheter  into  the  cerebrospinal  fluid  (CSF)  (intrathecal)  or  an  epidural  vein  (intravascular)  could  lead  to  catastrophic  complications.  Positive  aspiration  of  blood  or  CSF  from  the  catheter  confirms  catheter  misplacement.  However,  the  absence  of  an  aspirate  cannot  rule  out  whether  or  not  the  catheter  is  actually  in  the  epidural  space.  The  incidence  of  false  negative  aspiration  is  lower  for  multiorifice  epidural  catheters  (<1%)  compared  to  single-hole  catheters  (2%).  Aspiration  of  fluid  may  fail  due  to  low  epidural  venous  pressure,  air  locking  within  a  filter,  mechanical  obstruction  due  to  tissue  or  blood,  or  simply  incorrect  identification  of  the  aspirate.  For  these  reasons,  a  “test  dose”  should  be  administered  subsequent  to  epidural  catheter  placement  and  prior  to  incremental  dosing  of  small  volumes  of  local  anesthetic.