Dexamethasone added to levobupivacaine prolongs the duration of interscalene brachial plexus block and decreases rebound pain after arthroscopic rotator cuff repair.

Abstract

Background: It has been reported that the addition of dexamethasone to interscalene brachial plexus block (ISBPB) prolongs the duration of the block effect. However, there have been no studies focusing on the effects of dexamethasone on rebound pain after the block effect has worn off. The aim of this study was to investigate the effect on postoperative pain when dexamethasone was added to ISBPB for arthroscopic rotator cuff repair (ARCR). Methods: In this multicenter, single-blinded, and randomized controlled study, 54 patients (33 males, 21 females) who received ARCR were randomly assigned to group L (ISBPB with 20 cc of 0.25% levobupivacaine; 21 patients) or group LD (ISBPB with 20 cc of 0.25% levobupivacaine + 3.3 mg dexamethasone; 33 patients). The primary outcome was the visual analog scale (VAS) for pain after the block effect had worn off. Secondary outcomes were the duration of analgesia, the time to the first request for additional analgesic, the number of additional doses of analgesic, and complications. Results: The VAS scores on postoperative days 0 and 1 were significantly lower in group LD than group L (P = .005, .035). This indicated that the rebound pain was relieved in group LD. After postoperative day 1, there was no significant difference in VAS score (P = .43 and .19 for days 2 and 3, respectively). The duration of analgesia was significantly longer in group LD than group L (P < .001). The time to the first request for additional analgesic was significantly longer in group LD than group L (P < .001). The number of additional doses of analgesic was significantly lower in group LD (P < .001). Conclusion: In ARCR, the addition of dexamethasone to levobupivacaine not only prolongs the duration of ISBPB but also relieves rebound pain after the block effect wears off.