Regional infraclavicular blocks via the coracoid approach for below-elbow surgery: a comparison between ultrasound guidance with, or without, nerve stimulation

This randomised, observer-blinded study compared brachial plexus infraclavicular block under ultrasound guidance with, or without, nerve stimulation, for patients undergoing below-elbow surgery. Sixty-six patients, aged 18-70 years, with American Society Anesthesiologists’ status I, II or III, were randomised into two groups. Brachial plexus infraclavicular block achieved success rates of 76% in the ultrasound guidance without nerve stimulation group and 82% in the ultrasound guidance with nerve stimulation group, but was not significantly different (p-value 0.55). Block supplementation rates were 18.2% in the ultrasound guidance without nerve stimulation group vs. 12.2% in the ultrasound guidance with nerve stimulation group (p-value 0.55), resulting in 100% of the ultrasound guidance without nerve stimulation group reaching complete successful block, compared to 97% of the ultrasound guidance with nerve stimulation group. The mean performance time was significantly shorter in the ultrasound guidance without nerve stimulation group compared to the ultrasound guidance with nerve stimulation group (8.9 ± 3.9 minutes and 14.7 ± 3.3 minutes, respectively, p-value 0.001). Block onset time was 24.39 ± 4.3 minutes and 21.51 ± 2.4 minutes for the ultrasound guidance without nerve stimulation group and the ultrasound guidance with nerve stimulation group, respectively. The block onset time was significantly different between the groups (mean difference of 2.88, p-value 0.023). However, there was no difference in the time to readiness for surgery or surgical analgesia between the groups: ultrasound guidance without nerve stimulation (33.3 ± 8 minutes), and ultrasound guidance with nerve stimulation (36 ± 6 minutes) (p-value 0.09). Patients’ satisfaction was 93.9% vs. 87.9% in the ultrasound guidance without nerve stimulation group and the ultrasound guidance with nerve stimulation group, respectively (p-value 0.39). In this study, the use of ultrasound guidance alone for brachial plexus infraclavicular block provided rapid performance and yielded a high success rate without the aid of a nerve stimulator.Keywords: brachial plexus infraclavicular block, coracoid approach, nerve stimulation, ultrasound guidanceSouth Afr J Anaesth Analg 2013;19(5):263-26