Comparison of efficacy of intra-articular plain bupivacaine and bupivacaine with adjuvants (dexmedetomidine and magnesium sulfate) for postoperative analgesia in arthroscopic knee surgeries: A prospective, randomized controlled trial

Context: Intra-articular (IA) bupivacaine and adjuvants are used in multimodal analgesia for knee arthroscopy. Aims: To evaluate the efficacy of IA plain bupivacaine and bupivacaine with adjuvants (dexmedetomidine and magnesium [Mg] sulfate) for postoperative analgesia in knee arthroscopy. Settings and Design: This was a randomized controlled study in a tertiary care hospital. Methodology: Fifty-four patients were randomly allocated to receive 20 ml of study drug, 0.25% bupivacaine (Group B), 0.25% bupivacaine with 0.5 μg/kg of dexmedetomidine (Group D), and 0.25% bupivacaine with 10 mg/kg of Mg sulfate (Group M). Duration of analgesia, visual analog score for pain at rest (VAS-R) and movement (VAS-M), and number of times rescue analgesics were given in the first 24 h of postoperative period were assessed. Vital parameters and any side effects of the drugs were also noted at immediate (0, 5, 10, 15, and 30 min, 1 h) and late postoperative period (2, 4, 6, 12 and 24 h). Results: Duration of analgesia was prolonged in bupivacaine-dexmedetomidine and bupivacaine-Mg sulphate groups as compared to bupivacaine alone (5.97 ± 1.76 h, 13.44 ± 7.87 h, and 14.61 ± 8.83 h in Groups B, D, and M, respectively; P = 0.001). The VAS-R and VAS-M were less with Group D and Group M compared to Group B (P = 0.002 in VAS-R and P = 0.004 in VAS-M). The number of times rescue analgesic used was more in the Group B (2.06 ± 0.8, 0.94 ± 0.8, and 0.89 ± 0.9 in Groups B, D, and M, respectively; P < 0.001). The hemodynamic parameters were comparable and no side effects were noted among the three groups. Conclusion: IA bupivacaine with adjuvants prolongs duration and improves quality of postoperative analgesia as compared to bupivacaine alone.