Comparison of the efficacy of epidural nalbuphine versus dexmedetomidine on the characteristics of spinal anaesthesia in patients undergoing lower limb orthopaedic surgeries: A prospective randomised, double-blind, placebo-controlled study

Abstract

Background: Using adjuvants to local anaesthetic agents either intrathecally or epidurally is a common practice for achieving longer duration of a denser neuraxial block to provide adequate intraoperative conditions, for the length of the procedure. Methods: We compared the efficacy of epidural dexmedetomidine or nalbuphine on the characteristics of spinal anaesthesia in patients undergoing lower limb orthopaedic surgeries. Ninety patients were randomly allocated to three groups (n = 30 each). Group D received dexmedetomidine 1.5 μg/kg diluted to 5 mL; Group N received nalbuphine 0.2 mg/kg diluted to 5 mL and Group S received 5 mL of normal saline epidurally 10 min before receiving subarachnoid block (SAB) with 0.5% heavy bupivacaine. Results: The three groups were comparable demographically and haemodynamically. Significantly shorter time for the onset of sensory and motor block (sec), longer duration of sensory and motor blockade (min), higher sedation scores intraoperatively and postoperatively were observed in GroupD compared to other two groups. VAS scores were lower in Group D for a significantly longer period postoperatively, at 60 min, 120 min and 180 min than in other two groups (P < 0.05). Conclusions: Both dexmedetomidine and nalbuphine were found to be useful and safe epidural adjuvants when given prior to SAB. Dexmedetomidine was found to be a better choice of epidural adjuvant when compared to nalbuphine in terms of earlier onset and longer duration of both sensory and motor block, longer post-operative analgesia and useful intraoperative sedation.

Keywords

• central neuraxial block
• dexmedetomidine
• nalbuphine