Background and Aims Continuous interscalene brachial plexus block (CISB) provides analgesia after shoulder surgery. However, when catheter tip migration occurs, pain relief is degraded. We previously reported that catheter tip migration occurred at a rate of 44.8% during CISB for 48 hours regardless of catheter insertion length change when a conventional catheter was used and this migration decreased the analgesic effects. Reducing the migration rate is required to improve postoperative analgesia. Using a catheter of a different shape, like a self-coiling catheter, may help decrease tip migration. We therefore prospectively observed the catheter tip position of self-coiling catheters using ultrasound and studied its analgesic effect during CISB after shoulder surgery.

Methods After receiving IRB approval and informed consent, we studied 19 consecutive patients undergoing shoulder surgery who received the posterior in-plane approach to CISB under ultrasound-guidance. A self-coiling catheter was inserted for postoperative infusion for 48 hours. Using ultrasound, catheter tip location was assessed immediately after surgery and at 24 and 48 hours after block procedure. Pain scores, analgesic requirements, sensory and motor blockade were also assessed.

Results Under ultrasound, a catheter tip was found to be migrated in 2 patients (10.5%) including one patient with no catheter-at-skin change during CISB. Pain was well controlled for 48 hours.

• Download figure
• Open in new tab
• Download powerpoint

Abstract 154 Figure 1

Conclusions Catheter tip migration can occur even with a self-coiling catheter. However, since the incidence rate was almost one quarter of that with a conventional catheter, a comparative randomized study to confirm the present findings is warranted.