A Study on the Efficacy of the Addition of Low Dose Dexmedetomidine as an Adjuvant to Lignocaine in Intravenous Regional Anaesthesia (IVRA).

Abstract

Intravenous Regional Anaesthesia (IVRA) is a simple, effective method of providing anaesthesia for short duration surgical procedures on the extremities, its chief drawbacks are tourniquet pain, short duration of block and absence of post-operative analgesia. Dexmedetomidine is known to reduce anaesthetic requirements and also provide analgesia to the patient. To evaluate the efficacy of dexmedetomidine as an adjuvant to lignocaine in IVRA with respect to the quality of the block, tourniquet pain and post-operative analgesia. A prospective, randomized, double-blinded study was conducted on 60 patients scheduled for orthopaedic surgery of the upper limb, of American Society of Anaesthesiologist's physical status grades I and II. They were divided into two groups of 30 each. The control group C received 40ml of 0.5% lignocaine with saline and Group D received dexmedetomidine 0.5μg/kg added to 40ml of 0.5% lignocaine. The time taken for the onset and recovery of sensory and motor block, incidence of tourniquet pain, intra-operative and post-operative Visual Analogue Scale (VAS) scores, duration of post-operative analgesia and any side effects were noted. Student t-test was used for evaluation of the demographic data, haemodynamic variables, the onset and recovery times of block, duration of analgesia and intra-operative analgesic consumption and tourniquet pain. Friedman's test was used for intra-operative and post-operative VAS and sedation scores. The onset time of both sensory and motor block were significantly shortened, the recovery of sensory and motor block was prolonged, the incidence of tourniquet pain was comparatively lesser and there was significantly increased duration of post-operative analgesia in the dexmedetomidine group. Haemodynamic parameters were similar in both groups. The addition of 0.5μg/kg of dexmedetomidine as an adjuvant to IVRA effectively enhances the anaesthesia and post-operative analgesia obtained with lignocaine. The low dose of dexmedetomidine was effective and did not cause any major side effects.