addition of dexmedetomidine to lidocaine improves the quality of intravenous regional anesthesia block

ABSTRACT

The addition of alpha [2]-adrenoceptor agonists to local anesthetic solutions provides better analgesic properties when used for local, spinal, epidural or peripheral blocks. The present study was designed to test the hypothesis that the addition of dexmedetomidine ['highly selective and specific alpha[2]-adrenoceptor agonist] may improve the quality of IV regional anesthesia block during upper extremities surgery. Forty adult patients assigned for carpal tunnel decompression under regional IV anesthesia, were allocated randomly in a double blind, randomised study to receive 40 ml of 0.5% lidocaine solution and either 1 ml of normal soline or 100 micro g dexmedetmoidine [Precedex-Abbot] as 1ml solution. Pain at tourniquet site as well as surgical site was rated on a visual analogue scale [VAS], and a verbal rating scale [VRS] every 15 min during tourniquet placement and every 15 minute for 1 hour after tourniquet deflation. Sedation score, arterial blood pressure heart rate, arterial O[2] saturation and the duration of postoperative analgesia were also recorded. VAS and VRS scores were significantly lower in the precedex group 15, 30 and 45 minutes after tourniquet inflation at both surgical and tourniquet sites. Also it was significantly lower in the precedex group at surgical site after tourniquet deflation. There was no significant difference between both groups as regards the duration of tolerance of distal tourniquet, arterial blood pressure, O[2] saturation as well as sedation scores. The duration of postoperative analgesia was significantly longer in the precedex group. We concluded that dexmedetomidine improves the quality of regional IV block when added to lidocaine solution it decreases tourniquet pain, increases analgesia at surgical site and prolongs the duration of postoperative analgesia, without any significant systemic side effects