Ultrasound-guided costoclavicular vs. axillary brachial plexus block: A randomized clinical study

Brachial plexus is in a very compact state at the costoclavicular space (CCS) when compared to the axilla, where the individual nerves are separate. This study aimed to test the hypothesis that brachial plexus block (BPB) at the CCS would result in a faster onset of block as compared to the axillary approach of BPB.

Fifty patients who underwent surgeries below the level of mid-arm under ultrasound-guided BPB were randomly allocated to any one of the two study groups. Thirty milliliters of local anesthetic (LA), a mixture of 10-mL 2% lidocaine with 5-μg/mL adrenaline and 20-mL 0.5% bupivacaine, was deposited around the axillary artery (25-mL LA) and the musculocutaneous nerve (5-mL LA) or at the CCS, and performance time was noted. Observer blinded to the block procedure recorded the block onset time and success rate.

The mean (SD) onset times were comparable between the costoclavicular (CC) and axillary (AX) groups (12.0 ± 3.2 vs. 11.2 ± 2.9 min, respectively; P = 0.367). Group CC demonstrated a reduction in performance time compared to group AX (5.3 ± 1.9 vs. 8.0 ± 3 min, respectively; P < 0.05). All blocks were successful in both groups without any complications except for one patient in group AX who required a rescue block for radial nerve.

Costoclavicular and axillary ultrasound-guided BPBs resulted in similar onset times. However, the block performance time was longer for AX group compared to CC group. There were no intergroup differences found in terms of success rates.