Efficacy and Safety of Liposomal Bupivacaine and Ropivacaine in Upper Limb Surgery: a Randomized Controlled Trial

Study Design: This study employed a prospective, randomized, comparative, and double-blinded design to assess the superiority and non-inferiority of brachial plexus blockade combined with general anesthesia versus general anesthesia alone for postoperative analgesia in patients with upper limb injuries. Patient recruitment was conducted at Baogang Hospital, Inner Mongolia. This study was approved by the Medical Ethics Committee of Baogang Hospital, Inner Mongolia, and adhered to the principles of the Declaration of Helsinki and the Consolidated Standards of Reporting Trials (CONSORT) guidelines. All participants provided informed consent prior to enrollment.

Patients: Sixty patients aged two years or older with American Society of Anesthesiologists (ASA) physical status classifications I to III, scheduled for surgery due to upper limb injuries between February 2025 and May 2025, were enrolled in this study. Participants were randomly assigned to one of two groups, each containing 30 patients, receiving either brachial plexus blockade combined with general anesthesia or general anesthesia alone.

Randomization and Blinding：This study employed block randomization to generate the random allocation sequence. A block size of 6 was set, and the random sequence was generated using dedicated software (the blockrand package in R version 4.3.2). The allocation of the random sequence was performed by an independent third party, and allocation concealment was implemented using sequentially numbered, sealed, opaque envelopes. The research team remained blinded throughout the randomization process and was not involved in the generation or allocation of the random sequence.

Intervention：Upon arrival to the operating room, patients will be monitored with electrocardiography, blood pressure, and pulse oximetry. Patients will be placed in the prone position with their arms abducted and internally rotated. Ultrasound guidance will be used for all regional anesthesia procedures (SonoSite Edge II; Fujifilm SonoSite, Bothell, WA, USA) with a linear 13-6 MHz ultrasound probe (HFL50x; Fujifilm SonoSite, Bothell, WA, USA). For each block, a 5 mL test dose will be injected initially, followed by observation for clinical signs of a successful block. After confirming correct placement, the remaining dose of the anesthetic agent will be injected. Following administration of the regional anesthesia, general anesthesia with endotracheal intubation will be performed. Anesthesia induction will be achieved using propofol (1.5-2 mg/kg i.v.), rocuronium (1-2 mg/kg i.v.), and fentanyl (1-2 μg/kg i.v.). Anesthesia will be maintained using sevoflurane or desflurane, with inhaled concentration adjusted based on Bispectral Index (BIS) monitoring. A continuous infusion of remifentanil (0.05-0.2 μg/kg/min) will be administered, with adjustments to maintain blood pressure and heart rate within ±20% of baseline values. Following induction, patients will be mechanically ventilated in pressure-regulated volume control (PRVC) mode. The ventilator (Aestiva; GE Healthcare, Waukesha, Wisconsin, USA) settings will be: tidal volume 6-8 mL/kg, positive end-expiratory pressure 0 cm H2O, inspiratory to expiratory ratio 1:2, respiratory rate 16 breaths per minute (BPM), and fraction of inspired oxygen 41%.

Continuous Brachial Plexus Block Procedure: Patients were positioned supine with the head slightly turned to the contralateral side to expose the supraclavicular fossa. The injection site was prepared using standard aseptic techniques. Under ultrasound guidance, a needle was advanced to the vicinity of the brachial plexus. Aspiration was performed to confirm the absence of blood return before the slow, incremental injection of either liposomal bupivacaine [adult dose: 133 mg (10 mL) to 266 mg (20 mL)] or ropivacaine [adult dose: 20 mL of 0.5% ropivacaine, administered via continuous infusion at a rate of 5-10 mL/h; pediatric dose: 0.1% ropivacaine at 0.1-0.2 mL/kg, administered via continuous infusion at 0.05-0.15 mL/kg/h]. Patient responses were closely monitored throughout the procedure.