Post-Operative Analgesic Effect of Bupivacaine alone and with Dexmedetomidine in Wound Instillation for Lumbar Laminectomy: A Randomised Control Trial

Background: Dexmedetomidine has been used as an effective adjuvant to local anaesthetics in peripheral nerve blocks and at incision site. We studied the effect of addition of dexmedetomidine as an adjuvant to bupivacaine in wound instillation for postoperative analgesia. Aims To compare the postoperative analgesic effect of bupivacaine alone and in addition of dexmedetomidine to bupivacaine in wound instillation for lumbar laminectomy.

Study Design: Prospective, randomised, double blind study.

Methodology: Sixty adults of ASA grade I-II scheduled for elective lumbar laminectomy under general anaesthesia were randomly allocated into two groups. Group B(control group) patients received wound instillation with 20ml of 0.25% bupivacaine at the end of surgery and Group D patients received 2μgm.kg-1dexmedetomidine diluted in 20 ml 0.25% bupivacaine as instillation over incision site. If the NRS exceeded ‘4’ at any point of time, rescue analgesia with inj. Diclofenac 75 mg deep intramuscular was administered. Post- operative pain score, duration of analgesia, total rescue analgesic required in 24 h, incidence of side effects such as bradycardia, hypotension, sedation, nausea and vomiting were compared between the groups.

Results: Dexmedetomidine group has better pain score, longer duration of effective analgesia, lower percentage of patients requiring rescue analgesic and less no of doses of rescue analgesic required in first 24 h.

Conclusion: We conclude that dexmedetomidine 2µg.kg-1 is an effective adjuvant to bupivacaine for wound instillation in terms of quality and duration of postoperative analgesia following lumbar laminectomy.