Preliminary evaluation of infraclavicular catheters inserted using ultrasound guidance: through-the-catheter anesthesia is not inferior to through-the-needle blocks

Background and Objectives: This prospective study compared the initial block quality and surgical anesthesia rates of ultrasound -guided infraclavicular blocks with local- anesthetic injected through a catheter versus through a needle. We hypothesized that positioning of the catheter immediately posterior to the- axillary artery would produce through-the- catheter (TTC) anesthesia with rates of complete block not inferior to through-the-needle (TTN) injection. Methods: Eighty patients undergoing hand or forearm surgery extensive enough to require regional anesthesia were randomized into 2 groups of 40. In group TTN, local anesthetic was deposited posterior, lateral, and medial to the axillary artery using as few injections as necessary. In group TTC, a 20-gauge, multiorifice catheter was positioned between the posterior wall of the axillary artery and the posterior cord of the brachial plexus. All blocks were performed by use of ultrasound visualization with a 6-MHz to 10-MHz 38-mm linear probe. Local-anesthetic solution consisted of 0.5 mL/kg lidocaine 2% with epinephrine. Sensory and motor blocks, as well as supplementation rates, were evaluated for the musculocutaneous, median, radial, and ulnar nerves. Results: Complete sensory block of all nerve territories was achieved in 92% of patients in group TTN and 90% in group TTC (P =.51). In group TTN, 90% of patients had satisfactory anesthesia for surgery (no discomfort and no need for anesthetic supplementation of any type) compared with 92% in group TTC (P =.51). Conclusion: Ultrasound-guided TTC infraclavicular block produced perioperative anesthesia that was not inferior to a TTN technique.