Comparison between dexmedetomidine and verapamil as anadjuvant to local anesthesia in intravenous regional anesthesia in upper limb orthopedic surgery: a randomized double-blind prospective study

Background The use of intravenous regional anesthesia has increased significantly in recent years. Adjuvants are frequently added to local anesthetics to prolong analgesia following peripheral nerve blockade. Objective This randomized double-blind prospective study was designed to compare the effectiveness of adding dexmedetomidine (α2 adrenoceptor agonist) or verapamil (calcium channel antagonist) as an adjunct to lidocaine in upper limb orthopedic surgery. Patients and methods Sixty adult patients scheduled for elective upper limb orthopedic surgery were divided into three groups: the lidocaine group, in which patients received 3mg/kg of lidocaine 2% diluted with saline to a total volume of 40ml; the lidocaine dexmedetomidine group, in which patients received 0.5 μg/kg of dexmedetomidine plus 3mg/kg of lidocaine 2%; and the lidocaine verapamil group, in which patients received 2.5mg of verapamil plus 3mg/kg of lidocaine 2%. The onset and duration of sensory and motor block were recorded. Postoperative Visual Analog Score, onset of tourniquet pain, duration of analgesia, and total analgesic requirements at the 12th postoperative hour were monitored. Results Adding dexmedetomidine or verapamil to lidocaine causes faster onset and prolonged recovery of sensory and motor block and improvement of postoperative analgesia, without causing side effects compared with lidocaine alone. Conclusion The use of either verapamil or dexmedetomidine as an adjuvant to lidocaine solution causes equal improvement of the quality of anesthesia in intravenous regional anesthesia of upper limb orthopedic surgeries.