Ultrasonography Versus Peripheral Nerve Stimulation For Supraclavicular Brachial Plexus Block In Elective Upper-Limb Surgery: A Systematic Review And Meta-Analysis

Abstract

Background: Supraclavicular brachial plexus block is a workhorse regional technique for operations below the mid-humerus. Two guidance modalities dominate contemporary practice—real-time ultrasound (US) imaging and peripheral nerve stimulation (PNS). Their relative performance is still debated.

Objective: To compare block success, performance time, onset, duration, and complications of US-guided versus PNS-guided supraclavicular blocks in elective upper-limb surgery.

Methods: MEDLINE, Embase, CENTRAL, Scopus, Web of Science, and ClinicalTrials.gov were searched to 1 July 2025. Randomized or quasi-randomized trials and comparative cohort studies of adults undergoing elective upper-limb surgery with supraclavicular blocks under US or PNS guidance were eligible. Two reviewers independently screened, extracted data, and assessed risk of bias (RoB 2 or Newcastle-Ottawa). Random-effects meta-analysis generated pooled risk ratios (RR) for categorical outcomes and mean differences (MD) for continuous variables. Heterogeneity was explored with I² and prespecified subgroup and sensitivity analyses. Quality of evidence was appraised via GRADE.

Results: Twenty-nine studies (n = 2,814) met inclusion: 16 RCTs, 13 prospective cohorts. US guidance improved complete sensory block (RR 1.12, 95 % CI 1.07–1.18) and reduced performance time (MD –2.3 min, 95 % CI –3.0 to –1.6). Onset of sensory (MD –2.9 min) and motor block (MD –3.4 min) was faster with US, and block failure fell by 64 % (RR 0.36, 95 % CI 0.24–0.55). Pneumothorax occurred only in PNS arms (5 events). Evidence quality was moderate for critical outcomes. Publication bias was low on funnel-plot inspection.

Conclusions: Ultrasound guidance provides modest but clinically meaningful gains in efficacy and safety over PNS for supraclavicular blocks. Routine US adoption is justified where equipment and expertise exist; PNS remains reasonable when US is unavailable. Future trials should focus on cost-effectiveness and learning-curve endpoints.