1. 2021;24;E15-E21A Randomized Comparison Between Two Injections from Two Planes versus Two Injections with a Uniplanar Approach for Ultrasound-Guided Supraclavicular Block
   Randomized Controlled Trial
   Mi Geum Lee, MD, PhD, Hyeon Ju Shin, MD, PhD, Young Jin Chang, MD, PhD, Hee Yeon Park, MD, PhD, Yun Suk Choi, MD, PhD, and Ji Yeon Lee, MD, PhD.

BACKGROUND: The brachial plexus courses along the lateral to posterior aspect of the subclavian artery located within the supraclavicular region as a trunk or division. Therefore we hypothesized that 2 injections, one along the lateral and one along the posterior aspect of the brachial plexus, could be performed by changing the angle of the ultrasound probe, thereby achieving a 3-dimensional (3-D) even distribution of local anesthetics. Previously, we confirmed the efficacy of this type of approach with that of a single cluster approach. These findings represent a subsequent study.

OBJECTIVES: This study was conducted to confirm the superiority of block quality achieved by 2 injections from 2 planes (control group; group C) over 2 injections in one plane (experimental group; group E).

STUDY DESIGN: A randomized, controlled trial.

SETTING: Department of Anesthesiology and Pain Medicine, Gachon University Gil Medical Center.

METHODS: In group C (n = 35), the brachial plexus sheath was penetrated in 2 planes by anteriorly altering the angle of the ultrasound probe without changing its position. In group E (n = 35), the upper and lower portions of the brachial plexus sheath were penetrated in one plane. A total of 15 mL of lidocaine 1.5% containing epinephrine (1:200,000) was injected at each point in both groups. The ultrasound-guided supraclavicular brachial plexus block was evaluated every 5 minutes for 30 minutes. The main outcome variables were rates of blockage of all 4 nerves and ulnar nerve sparing.

RESULTS: The rate of blockage of all 4 nerves (median, ulnar, radial, and musculocutaneous nerves) was not significantly different between the 2 groups (94% in group C vs. 86% in group E, respectively; P = 0.232). The number of spared ulnar nerves was similar (1 vs. 5, respectively; P = 0.088). Group procedure times, onset times, and Visual Analog Scale scores for the blocks were similar.

LIMITATIONS: For the 2 plane, 2 injection approach, only 2-D imaging was performed rather than 3-D imaging.

CONCLUSIONS: Two injections performed in one plane offered similar benefits to 2 injections performed in 2 planes. The 2 techniques provided comparable block qualities and could be viewed as equally effective alternatives.

KEY WORDS: Brachial plexus block, multiple injection, supraclavicular block, ultrasound