Hemidiaphragmatic paralysis following costoclavicular versus supraclavicular brachial plexus block: a randomized controlled trial

Costoclavicular brachial plexus block is emerging as a promising infraclavicular approach performed just below the clavicle. However, there are relatively little data regarding the hemidiaphragmatic paralysis (HDP) compared to the commonly performed supraclavicular block. We hypothesized that the incidence of HDP in costoclavicular block is lower than supraclavicular block like classical infraclavicular approach. Eighty patients were randomly assigned to ultrasound-guided supraclavicular (group S) or costoclavicular (group C) block with 25 mL of local anesthetics (1:1 mixture of 1% lidocaine and 0.75% ropivacaine). The primary outcome was the incidence of HDP, defined as less than 20% of fractional change in the diaphragm thickness on ultrasound M-mode. Also, pulmonary function test and chest radiograph were assessed before and after the surgery. The incidence of HDP was 4/35 (11.4%) in the group C and 19/40 (47.5%) in the group S (risk difference, - 36%; 95% CI - 54 to - 17%; P = 0.002). The mean (SD) change of DTF values were 30.3% (44.0) and 56.9% (39.3) in the group C and S, respectively (difference in means, - 26.6%; 95% CI - 45.8 to - 7.4%; P = 0.007). The pulmonary function was more preserved in group C than in group S. The determined diagnostic cut off value of the diaphragm elevation on chest radiograph was 29 mm. Despite the very contiguous location of the two approaches around the clavicle, costoclavicular block can significantly reduce the risk of HDP compared with supraclavicular block.