Effect of continuous interscalene block with ropivacaine at a low concentration on postoperative pain relief after arthroscopic rotator cuff reconstruction

Background: The analgesic effect of continuous interscalene block with ropivacaine at a low concentration was compared with that of single-shot interscalene block after arthroscopic rotator cuff reconstruction (ARCR). Methods: Eighty patients scheduled to undergo ARCR from January 2010 to March 2012 were assigned to a group receiving postoperative continuous interscalene block (continuous group, n=46) and a group receiving single-shot interscalne block (single group, n=34). In both groups, ultrasound-guided interscalene block was performed before induction of general anesthesia. In the Continuous group, continuous interscalene infusion with 0.1% ropivacaine was performed up to postoperative 48 hours. Pain intensity (Prince-Henry scale), additional use of analgesics, and adverse effects were recorded. Statistical analysis was performed with Mann-Whitney test, and P<0.05 was considered to be significant. Results: Pain intensity in the continuous group was significantly lower than that in the single group on the night of the day of operation and the morning of the first postoperative day. The frequency of use of additional analgesic in the continuous group was approximately half of that in the single group. No complete motor block was recorded during continuous infusion of ropivacaine. Conclusions: Postoperative continuous interscalene block with 0.1% ropivacaine provided sufficient analgesia without complete motor block.