Background: The supraclavicular nerve block is a useful alternative to general anesthesia for upper limb surgery. Previous research investigated the effect of adjuvant, but its role in the context of a reduced volume of a local anaesthetic drug under ultrasound-guided blocks remains unknown.
Aim of the Study: To determine the enhancing effect of dexmedetomidine or midazolam as a local anaesthetic adjuvant to bupivacaine.
Patients and Methods: A prospective double-blind randomized clinical trial, included 90 patients arranged for upper limb vascular surgery. Two groups are comprised; BD group [45 patients]: patients who received ultrasound-guided supraclavicular regional block with injection of 20 ml Bupivacaine 0.25% + 10 ml Lidocaine Hydrochloride 2% + 1µ/kg Dexmedetomidine, and BM group [45 patients]: Patients received ultrasound-guided supraclavicular regional block with an injection of 20 ml Bupivacaine 0.25% + 10 ml Lidocaine Hydrochloride 2% + 50µ/kg Midazolam. The primary outcome was duration of post-operative analgesia.
Results: The BD group had a statistically significant longer duration of analgesia compared to the BM group. Patients in the BD group had significantly higher scores on the Ramsay Sedation Scale and VAS starting from 30 and 45 minutes intraoperatively, respectively, and these scores continued to be higher until 6 hours postoperatively. However, there were no significant differences between the two groups regarding blood pressure measurement along the follow-up period.
Conclusion: Adding dexmedetomidine to bupivacaine for supraclavicular brachial plexus block was found to be more effective than adding midazolam in extending the duration of both sensory and motor block.