RESUMO
OBJECTIVE: The aim: To compare the different doses of dexmedetomidine as adjuvant to lidocaine in intravenous regional anesthesia. PATIENTS AND METHODS: Materials and methods: Ninety patients participated in this study in Al-Yarmook teaching hospital in period between January 1st 2016 - July 1st 2016, divided randomly in to 3 groups. Group 1: received lidocaine diluted with normal saline; Group 2 - lidocaine with dexmedetomidine 0.5 µg/kg; Group3 -lidocaine with dexmedetomidine 1 µg/kg. Statistical analysis was done by IBM SPSS program version 20 and Microsoft excel version 2010 , the means were compared by ANOVA methods and Dunnett t3, significance between groups were recorded if p value less than 0.05. RESULTS: Results: Dexmedetomidine was effective in decreasing the sensory block onset time and motor block onset time and prolongation of the motor and sensory recovery with no significant hemodynamic changes than is often shown by the lidocaine alone, it also prolongs the time interval for analgesic requirement after the operation. For the group 3 it was faster than in group 2 and faster than in group 1 significantly (p value < 0.001) to form a sensory block onset and motor block onset; and it took significantly more time to recover the sensation than in group 1 (p value <0.001) and 2 (p value <0.002) , and more time for motor recovery than in group 1 (p value < 0.001). Group 3 had the longest time to call for the analgesia after operation than group 2 and 3 (p value < 0.001); and group 2 also had longer time for the same process than group 1 (p value < 0.001). CONCLUSION: Conclusions: A variety of adjuvants have been used in IVRA to decrease tourniquet pain, improve block quality, and prolong analgesia after cuff deflation. Opioids are relatively ineffective and cause nausea, vomiting, and dizziness after tourniquet deflation, but several NSAIDs have been shown to be beneficial, dexmedetomidine improves block quality and postoperative analgesia.