title: Use of imaging agent to determine postoperative indwelling epidural catheter position.
abstract: BACKGROUND
  Epidural anesthesia is widely used to provide pain relief, whether for surgical anesthesia, postoperative analgesia, treatment of chronic pain, or to facilitate painless childbirth. In many cases, however, the epidural catheter is inserted blindly and the indwelling catheter position is almost always uncertain.
  
  
  METHODS
  In this study, the loss-of-resistance technique was used and an imaging agent was injected through the indwelling epidural anesthesia catheter to confirm the position of its tip and examine the migration rate. Study subjects were patients scheduled to undergo surgery using general anesthesia combined with epidural anesthesia. Placement of the epidural catheter was confirmed postoperatively by injection of an imaging agent and X-ray imaging.
  
  
  RESULTS
  The indwelling epidural catheter was placed between upper thoracic vertebrae (n = 83; incorrect placement, n = 5), lower thoracic vertebrae (n = 123; incorrect placement, n = 5), and lower thoracic vertebra-lumbar vertebra (n = 46; incorrect placement, n = 7). In this study, a relatively high frequency of incorrectly placed epidural catheters using the loss-of-resistance technique was observed, and it was found that incorrect catheter placement resulted in inadequate analgesia during surgery.
  
  
  CONCLUSIONS
  Although the loss-of-resistance technique is easy and convenient as a method for epidural catheter placement, it frequently results in inadequate placement of epidural catheters. Care should be taken when performing this procedure.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Uchino
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hagiwara
authors.forename: Hideo
authors.initials: H
authors.lastname: Iwasaka
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Kudo
authors.forename: Junji
authors.initials: J
authors.lastname: Takatani
authors.forename: Akio
authors.initials: A
authors.lastname: Mizutani
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miura
authors.forename: Takayuki
authors.initials: T
authors.lastname: Noguchi