A Randomized Comparison Between 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg of Perineural Dexmedetomidine for Ultrasound-Guided Infraclavicular Block

This study will compare three different doses of perineural dexmedetomidine 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg as adjuvants to local anesthetics for ultrasound-guided infraclavicular brachial plexus blocks (ICBs). Our research hypothesis is that 1.33 mcg/kg will provide a 15%-longer duration than 1mcg/kg, which in turn will provide a 15%-longer duration than 0.67 mcg/kg. Since analgesic duration and sensory duration can be influenced by intake of pain medications and surgical trauma to small cutaneous nerves, respectively, we will select motor block duration as the main outcome to better target the action of dexmedetomidine on the brachial plexus.