A Comparative Study of Two Different Doses of Dexmedetomidine as Adjunct to Lignocaine in Intravenous Regional Anaesthesia of Upper Limb Surgeries

Introduction: Intravenous regional anaesthesia is a simple and cost effective technique for surgery involving the distal arm. Dexmetomidine which is about eight times more potent than clonidine has been used in bier's block and was shown to improve the quality of anaesthesia, torniquet pain and postoperative analgesic requirement. The aim of present study is to compare two different doses of dexmedetomidine (0.5 mu gm/kg and 1 mu gm/kg) as adjunct to Lignocaine in intravenous regional anaesthesia for upper limb surgeries. Also to evaluate dose related responses of dexmedetomidine on onset and quality of block, tourniquet pain and post operative analgesia. Material and Methods: This study included 60 patients of ASA class I and II of either sex aged between 17-70 years scheduled for various upper limb surgeries. Patients were randomly divided into two groups 30 each. They received 40 ml 0.5% lignocaine and either dexmedetomidine 0.5 mu gm/kg (group A) or dexmedetomidine 1 mu gm/kg (group B). None of the patient in 2 groups was premedicated sensory and motor block onset were noted. Postoperative pain score was recorded by using Visual analogue scale (VAS). Diclofenac was given I. M as rescue analgesia when VAS values reached >= 4. Duration of postoperative analgesia was noted from deflation of torniquet to VAS score of 4. Assessment of sedation was done using Ramsay sedation score at 30 minute, 60 minute and 90 minute intervals following torniquet deflation. Results: The onset of sensory and motor block in group B was significantly shorter than group A. Both the groups showed comparable low level of sedation. VAS score of group B was statistically lower than VAS score of group A. Quality of blockade among both groups was excellent. Conclusion: We concluded that addition of 1 mu gm/kg dexmedetomidine to lignocaine for IVRA improves quality of anaesthesia and postoperative analgesia in comparison to 0.5 mu gm/kg dexmedetomidine.