Upper-extremity Surgery

The costoclavicular approach of the infraclavicular brachial plexus block is widely used for upper extremity surgeries due to its reliable anatomy and high success rates. Patient positioning, particularly the degree of arm abduction, may influence the spread of local anesthetic and the characteristics of the block. However, the optimal arm abduction angle during this procedure remains unclear. This prospective randomized controlled trial aims to investigate the effect of two different arm abduction angles (90° and 120°) on block onset time and block success in patients undergoing hand, wrist, and forearm surgery under ultrasound-guided costoclavicular brachial plexus block. Patients will be randomly assigned to one of two groups according to the degree of arm abduction. The primary outcome is block onset time. Secondary outcomes include block success, sensory and motor block characteristics, perfusion index changes, hemodynamic parameters, readiness for surgery at 15 and 20 minutes, block performance time, need for additional anesthesia, postoperative neurological evaluation at 4 and 24 hours, complications, and patient satisfaction. The findings of this study are expected to provide evidence on optimal patient positioning to improve the effectiveness and reliability of ultrasound-guided costoclavicular brachial plexus 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.