Block performance indices of perivascular and perineural techniques of ultrasound-guided axillary block in upper limb surgeries: A comparative study.

BACKGROUND

Nerve block anesthesia is a common regional anesthesia used for upper limb surgeries because of its ability to target the operative site and provision of impressive postanesthetic pain relief. This randomized, single-blinded study compared the quality of block of the perineural (PN) and perivascular (PV) techniques of axillary brachial plexus block under ultrasound guidance.

METHODS

Sixty-six participants were recruited into either PV or PN groups. The local anesthetic (LA) comprised 14 ml of 0.5% bupivacaine, 14 ml of 1% lidocaine, and 2 ml of dexmedetomidine (50 μg/ml). Under ultrasound guidance, 6 ml of LA was deposited around the musculocutaneous nerve for both groups. For the PV group, 24 ml was deposited dorsal to the axillary artery while 8 ml each was deposited around median, radial, and ulnar nerves for the PN group.

RESULTS

The mean total procedure time in PN group was significantly longer than in the PV group (7.82 ± 0.95 min vs. 4.79 ± 1.11 min; P = 0.001). Participants in the PN group required more needle passes (66.7% required 4 passes while 81.8% required only 2 passes in the PV group). The success rate was 100% in PN group and 93.9% in PV group (P = 0.49).

CONCLUSION

The PV and PN techniques were comparable in terms of their success rates and total anesthesia-related times. The PN technique had higher success rate and faster block onset, but the PV provided a quicker performance time and fewer needle passes. Hence, PV technique may be preferable to PN for high-volume surgical units.