Comparison of Single and Double Injection Ultrasound-Guided Supraclavicular Block for Upper Limb Surgery: A...

The ongoing debate regarding the preferred technique between single-site and double-site injection procedures for supraclavicular block remains unresolved. We conducted this research to evaluate the clinical outcomes of single-site versus double-site injection in patients undergoing upper limb surgery.

A literature search was conducted up to September 2023 to identify randomized controlled trials (RCTs) comparing the single-site injection group (SG) with the double-site injection group (DG) for the supraclavicular block. The analysis was conducted using Review Manager 5.4, employing either a fixed-effects or random-effects model (PROSPERO; no. CRD42023492703).

Based on the 10 RCTs included in the quantitative analysis, there were no significant differences in success rates (i.e., the primary outcome), surgical anesthesia, total anesthesia-related time, time to first rescue analgesic, and adverse events. However, significant differences were observed in several secondary outcomes. SG showed advantages in terms of shorter performance time (mean difference [MD], -1.02 minutes [95% confidence interval [CI], -1.79 to -0.25; P = 0.01; I^2 = 91%]) and lower blockade pain scores (MD, -0.30 minutes [95% CI, -0.60 to 0.00; P = 0.05; I^2 = 0%]). Conversely, DG demonstrated superiority in terms of faster block onset time (MD, 5.73 minutes [95% CI, 4.91, 6.54; P < 0.00001; I^2 = 1%]), longer duration of the sensory block (MD, -71.77 minutes [95% CI, -139.50 to -4.03; P = 0.04; I^2 = 98%]), and longer duration of the motor block (MD, -33.13 minutes [95% CI, -39.64 to -26.63; P < 0.00001; I^2 = 0%]).

This meta-analysis provides evidence that SG and DG had equivalent success rates. SG revealed favorable outcomes in terms of shorter performance time and lower blockade pain scores. However, DG was considered superior in terms of faster block onset and longer durations of sensory and motor block.