Use of Imaging Agent to Determine Postoperative Indwelling Epidural Catheter Position

Abstract

BackgroundEpidural 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.MethodsIn 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.ResultsThe 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.ConclusionsAlthough 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.

Confirmation of Loss-of-Resistance for Epidural Analgesia

“…29 In turn, primary failure can be ascribed to misidentification of the epidural space or suboptimal catheter position. Primary epidural failure rates for labor and surgical analgesia vary between 2.0% and 16.9% in large studies (n > 200) published over the last 10 years (2005-2014) [30][31][32][33] (Table 1). Because prudence dictates that LA boluses be fragmented and administered through the catheter (and not the needle), it can be difficult to ascertain if these reported failure rates stem from misidentification of the epidural space (nonepidural LOR) or catheter malposition (eg, intervertebral foramen).…”

“…In addition to guiding the needle between spinous processes or laminas, 38 fluoroscopy (with contrast injection) enables confirmation of LOR obtained by the epidural needle, 36 as well as placement of the catheter tip 32 (Fig. 1).…”

The impact of fluoroscopic confirmation of thoracic imaging on accuracy of thoracic epidural catheter placement on postoperative pain control

“…These results support our hypothesis that patients with incorrect epidural catheter placement may receive adequate postoperative analgesia, while also highlighting the importance of identifying the correct catheter level at the time of insertion. Since it is unlikely that all patients with incorrect catheter placement will have uniform dye spread to reach the intended vertebral level (which is the epicenter of the expected nociception), the situation is more likely to result in failure of continuous TEA 34,45…”

Raman Spectroscopy Differentiates Each Tissue from the Skin to the Spinal Cord

“…14,16,22 However, its use is labor and time intensive, requires additional equipment and often manpower, and exposes the patient and medical personnel to radiation.…”

“…6 Numerous techniques have been proposed to improve localization of the epidural space, including the use of ultrasound, loss of resistance assistance devices, fluoroscopy, and optical devices. 7-22 However, these methods lack the resolution to identify each tissue in the path of an epidural needle.…”