A Comparison of Anesthetic Quality between Single and Septum-based Double Injection for Ultrasound-Guided Costoclavicular Block: A Randomized Controlled Trial.

In a costoclavicular (CC) approach of an ultrasound (US)-guided infraclavicular brachial plexus block (BPB), a septum between the lateral and the medial/posterior cords can result in an incomplete block. We hypothesized that double injections in each compartment between the septum would result in a higher success rate of BPB than a single injection in the center of the CC space.This study was conducted to confirm the superiority of block quality achieved by septum-based double injections (experimental group; group E) over single injection in the center of the CC space (control group; group C).A randomized, controlled trialSETTING: Department of Anesthesiology and Pain Medicine, Korea University College of Medicine, Anam Hospital.Sixty-eight patients who underwent upper extremity surgery randomly received a single (SI group, n = 34) or a septum-based double injection (DI group, n = 34) using the CC approach. Ten milliliters of 2% lidocaine, 10 mL of 0.75% ropivacaine, and 5 mL of normal saline were used for BPB in each group (total 25 mL). Sensory-motor blockade of the ipsilateral median, radial, ulnar, and musculocutaneous nerves was assessed by a blinded observer at 5-minute intervals for 30 minutes immediately after local anesthesia administration. The assessed variables were the success rate, the rate of all 4 nerves blockade, and onset time.Thirty minutes after the block, the success rate was significantly higher in the DI group than in the SI group (64.7% in the SI group vs 91.2% in the DI group, P = 0.009), and the rate of all 4 nerves blockade also significantly increased in the DI group compared to the SI group (44.1% in the SI group vs 91.2% in the DI group, P = 0). The onset time was significantly shortened in the DI group compared with the SI group (26.3 ± 5.6 min in the SI group vs 21.3 ± 6.2 min in the DI group, P = 0.010).We considered that the location of the septum was always between the lateral cord superficially and the medial/posterior cords below it. In some patients in whom the septum was not visible, a superficial lateral cord was injected first, and then deep medial and posterior cords were injected, assuming that the 2 compartments were divided by the septum.Compared with the SI, the septum-based DI of CC approach increased the success rate and the rate of all 4 nerves blockade and shortened the onset time.