Post-operative wound infiltration with dexmedetomidine and magnesium sulphate as adjuvant to levobupivacaine for lumbar laminectomy: a prospective, double blinded, randomized controlled study

Abstract

Background: Wound infiltration with local anaesthetic is safe and effective technique for providing postoperative analgesia following lumbar laminectomy. The objective of this study was to compare the efficacy of local wound infiltration on postoperative analgesia with levobupivacaine, levobupivacaine plus magnesium sulphate and levobupivacaine plus dexmedetomidine in patient undergoing lumbar laminectomy.Methods: Ninety adult patients were randomly allocated into three groups. After the completion of lumbar laminectomy, the drug was locally infiltrated into the paravertebral muscles on either side. Group L received 10 ml of 0.5% levobupivacaine plus 10 ml normal saline, group LM received 10 ml of 0.5% levobupivacaine plus 500 mg magnesium sulphate (1 ml) plus 9 ml normal saline, group LD received 10 ml of 0.5% levobupivacaine plus 50 µg dexmedetomidine (0.5 ml) plus 9.5 ml normal saline. Postoperative visual analogue scale (VAS) pain score at 0, 1, 2, 4, 6, 8, 12 and 24 hours, time to first rescue analgesic drug and its total dose, quality of recovery score (QoR) and side effects were noted.Results: Postoperative VAS was significantly higher in group L as compared to group LM and LD (p<0.05). The time to first rescue analgesic drug was significantly longer in group LD (11.07±7.20 hr) than group LM (6.20±2.64 hr) and group L (3.93±2.70 hr) (p<0.001). The QoR score was significantly better in group LD as compared to group LM and L postoperatively (<0.01).Conclusions: Addition of magnesium sulphate or dexmedetomidine to levobupivacaine for local wound infiltration demonstrated enhanced postoperative analgesia.