title: Use of colour Doppler and M-mode ultrasonography to confirm the location of an epidural catheter - a retrospective case series.
abstract: OBJECTIVE
  Epidural anesthesia and analgesia has a reported failure rate ranging from 13% to 32%. We describe a technique using colour Doppler and M-mode ultrasonography to determine the position of the epidural catheter after placement in adults.
  
  
  METHODS
  This retrospective review included 37 adult patients who received postoperative epidural analgesia and underwent technically difficult epidural catheter placement. The demographic characteristics, type of surgery, use of ultrasonography, method of insertion, intervertebral level, and success of epidural localization using colour Doppler were noted for each patient. Pain scores on postoperative day 1 and the presence of a patchy block were also reviewed.
  
  
  RESULTS
  Colour Doppler study helped to indicate the catheter's path from the skin to the epidural space during saline injection in 33 patients (89%). Saline flow within the epidural space (catheter tip confirmation) was successfully detected with colour Doppler in 25 patients (67.5%) and with M-mode ultrasonography in 28 patients (75%). Appropriate dermatomal analgesia was noted in 35 patients (94.5%) during local anesthetic infusion.
  
  
  CONCLUSIONS
  Our preliminary data suggest the feasibility of using colour Doppler and M-mode ultrasonography to confirm proper epidural catheter placement.
authors.affiliation: Department of General Anesthesiology and Department of Outcomes Research, Cleveland Clinic, 9500 Euclid Ave, E-30 Cleveland, Cleveland, OH, 44195, USA. elsharh@ccf.org.
authors.forename: Hesham
authors.initials: H
authors.lastname: Elsharkawy
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Abraham
authors.initials: A
authors.lastname: Sonny
authors.affiliation: Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Srinivasa Raghavan
authors.initials: SR
authors.lastname: Govindarajan
authors.affiliation: Department of Anesthesia, University of Toronto, Toronto, ON, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Chan
mesh_terms: D000368:Aged; D000767:Anesthesia, Epidural / Q000379:methods*; D002404:Catheterization / Q000379:methods*; D004824:Epidural Space; D006801:Humans; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D012189:Retrospective Studies; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D018084:Ultrasonography, Interventional / Q000379:methods*