Postoperative analgesic effect of bupivacaine alone and with dexmedetomidine in wound instillation for lumbar laminectomy: A randomized control trial

Dexmedetomidine has been used as an effective adjuvant to local anesthetics in peripheral nerve blocks and at the incision site.We compared the postoperative analgesic effect of bupivacaine alone and in addition of dexmedetomidine to bupivacaine in wound instillation during lumbar laminectomy.This was a prospective, double-blind, randomized control trial.Sixty adults of the American Society of Anesthesiologists Grade I-II scheduled for elective lumbar laminectomy under general anesthesia were randomly allocated into two groups. Group B (control group) patients received wound instillation with 20 mL of 0.25% bupivacaine at the end of surgery and Group D patients received 2 μg.kg-1 dexmedetomidine diluted in 20 mL 0.25% bupivacaine as instillation over the incision site. If the NRS exceeded "4" at any point of time, rescue analgesia with injection diclofenac 75 mg deep intramuscular was administered. Postoperative pain score, duration of analgesia, total rescue analgesic required in the first 24 h, and side effects were compared between the groups.Demographic data were comparable in both the groups. Duration of analgesia (19.93 ± 3.2 in Group D vs. 12.13 ± 1.8 in Group B) was significantly more in Group D, number of analgesic demands were less in group D as compared to Group B, and total rescue analgesic required (62.51 ± 39.13 vs. 95.68 ± 33.5) was significantly less in Group D as compared to Group B.We conclude that dexmedetomidine 2 μg.kg-1 is an effective adjuvant to bupivacaine for wound instillation in terms of quality and duration of postoperative analgesia following lumbar laminectomy.