Analgesia after arthroscopic rotator cuff repair: subacromial versus interscalene continuous infusion of ropivacaine.

OBJECTIVES

A continuous infusion of local anesthetic in the subacromial space has been shown to provide superior pain relief compared with placebo. This technique has been considered as an alternative to a continuous interscalene infusion. The aim of our study is to compare these 2 techniques for pain relief after arthroscopic rotator cuff repair.

METHODS

In a prospective randomized trial, 30 consecutive patients undergoing rotator cuff repair were included. An interscalene brachial plexus block was performed in all patients with mepivacaine 1.5% 30 mL. Then, 15 patients had an indwelling interscalene catheter inserted immediately after the block via a needle. Fifteen other patients had a subacromial catheter placed at the end of surgery by the surgeon. In both groups, a 2 mg/mL ropivacaine continuous infusion (5 mL/h) with PCA bolus (5 mL/30 min) was maintained for 48 hours. Pain was assessed in PACU and at 24 and 48 hours after surgery, at rest, and during passive motion. Total amount of oral morphine self-administered as rescue analgesia and cumulative 24-hour and 48-hour local anesthetic consumption were noted. Patient satisfaction and side effects were also noted.

RESULTS

Pain during motion in PACU (0 [0 to 60] v 40 [0 to 100] mm) and at 24 hours (10 [0 to 60] v 45 [20 to 100] mm), oral morphine (0 [0 to 6] v 3.5 [0 to 10] morphine capsules), and total amount of local anesthetic at 24 hours (122.5 [120 to 170] v 143 [129 to 250] mg) were lower in the continuous interscalene group. Local anesthetic side effects were less frequent in the continuous subacromial group. Satisfaction was comparable between groups.

CONCLUSION

After arthroscopic rotator cuff repair, continuous interscalene block provides better analgesia compared with continuous subacromial infusion but with an increased incidence of minor side effects.