Dexmedetomidine as an Adjuvant to Lignocaine for Intravenous Regional Anesthesia for Forearm and Hand Surgeries: A Prospective, Randomized, Controlled Study

Objective: Intravenous regional anesthesia (IVRA) is an effective anesthetic technique for surgical procedures of short duration involving the distal parts of the limbs. Intraoperative tourniquet pain is the major restraint of this technique, and to overcome this limitation, various adjuvants to local anesthetics have been used. This study investigated the effect of a fixed low dose of dexmedetomidine as an adjuvant to lignocaine on intraoperative tourniquet pain, onset of block, duration of block, and patient satisfaction.
Methods: A total of 100 adult patients with ASA grade I and II who were scheduled for upper limb surgery of approximately 1 hour in duration were randomly divided into two groups (n=50 in each group). Group A received 35 mL of preservative-free lignocaine alone and Group B received 35 mL of preservative-free lignocaine along with 30 μg of dexmedetomidine. The incidence of tourniquet pain, intraoperative fentanyl consumption, duration of onset and recovery of sensory and motor block after tourniquet deflation, postoperative numeric pain rating scale (NPRS) scores, duration of analgesia, and overall patient satisfaction were noted.
Result: The incidence of tourniquet pain and intraoperative fentanyl consumption were significantly lower in Group B. The onset and duration of sensory and motor blocks were faster and longer, respectively, in Group B. Postoperative NPRS scores were lower, duration of analgesia was longer, and overall patient satisfaction was better in the dexmedetomidine group.
Conclusion: Dexmedetomidine at a dose of 30 μg as a lignocaine adjuvant significantly reduces tourniquet pain and intraoperative fentanyl consumption in IVRA. Dexmedetomidine shortens the onset of block, prolongs the duration of block, and provides a more satisfactory anesthesia than lignocaine alone.