Interscalene block is applied to control acute postoperative pain after arthroscopic rotator cuff repair (ARCR), typically with single-shot interscalene block (SSIB) or continuous interscalene indwelling catheter analgesia (IICA), and dexamethasone (Dex) for extending the analgesic effect. This study investigated whether perineural Dex can extend the postoperative analgesic effect of SSIB to match that of IICA. A total of 130 patients were recruited and divided into two groups (Group D, SSIB with perineural Dex, n = 94; Group C, IICA, n = 36). The surgical and anesthetic processes were identical except for the method of nerve block. Pain was measured by a visual analog scale (VAS) at 6, 12, 24, and 48 h after ARCR. The number of each and the total analgesics used and adverse effects were compared. The duration of ARCR was longer in group D. The VAS score was higher in group C 6 h after ARCR, but there was no difference at other time points. More postoperative analgesics were administered to group C, and there was no difference in the number of adverse effects. In conclusion, combining perineural Dex with SSIB can reduce rebound hyperalgesia after 6 h and extend the duration of the analgesic effect to that of IICA. Therefore, IICA could be substituted with SSIB and Dex between at 6 and 48 h after ARCR.
Keywords: analgesic; arthroscopy; dexamethasone; interscalene block; perineural; rotator cuff repair.