Comparison of the transarterial axillary block and the ultrasound-guided infraclavicular block for upper extremity surgery: a prospective randomized trial.

Background and Objectives: The transarterial axillary block and the ultrasound-guided infraclavicular block are both effective methods of anesthetizing the upper extremity. This study compares these methods with respect to subjective postoperative dysesthesias, block adequacy, patient comfort, and patient satisfaction. Methods: Two hundred thirty-two patients were randomized to receive an ultrasound-guided infraclavicular block or a transarterial axillary block for upper extremity surgery. Block placement, motor and sensory testing, and block adequacy data were recorded. The subjects were contacted by a blinded research assistant at 2 and 10 days postoperatively to assess for the presence of dysesthesias and pain and to assess patient satisfaction. Results: The 2 techniques were similar with respect to block performance time and adequacy of the block for surgery. There was no significant difference between the blocks in terms of postoperative dysesthesias (23.9% in the axillary group vs 17.1% in the infraclavicular group at 2 days, P = 0.216, and 11.0% vs 6.31% at 10 days, P = 0.214). None of the dysesthesias were permanent. The infraclavicular block had a lower incidence of paresthesias during placement ( P = 0.035) and was associated with less pain at the block site ( P = 0.010 at 2 days, P = 0.002 at 10 days). More patients were willing to undergo the infraclavicular block as a future anesthetic when compared with the axillary block ( P = 0.025 at 10 days). Conclusions: There is no significant difference between the 2 techniques in terms of adequacy for surgery and subjective postoperative dysesthesias. The ultrasound-guided infraclavicular block is associated with greater patient comfort and willingness to undergo the same anesthetic when compared with the transarterial axillary block.