Participants

We recruited 24 patients who were 18 years or older, ASA I to III, and scheduled for elective hand, wrist, and forearm surgery. Exclusion criteria were as follows: local anesthetic allergies, chronic pain, coagulopathy, infection at the planned injection site, peripheral neurologic disease, and inability to comprehend study-related procedures.

The 24 patients were randomly divided into two groups: Arm Group and Axillary Group. Ultrasound-guided selective nerve block of the upper arm combined with general anesthesia were used in the Arm Group, while ultrasound-guided axillary brachial plexus block combined general anesthesia were used in the Axillary Group. On arrival in the preoperative room, all patients received standard monitoring, including noninvasive blood pressure, electrocardiogram, and pulse oximetry. A 20-gauge intravenous (IV) catheter was secured in the opposite forearm and midazolam 1 mg and fentanyl 20 μg were administered IV before nerve blockade unless contraindicated.An attending anesthesiologist with > 5 years experience and a case load of at least 200 blocks/year performed all blocks in the preoperative room using an ultrasound machine (SonoSite X-Porte, SonoSite, Bothell, WA, USA) with a linear 38 mm, 15–6 MHz probe, and 5-cm insulated block needles were used to guide a 25 ml injection of ropivacaine 0.375%. Another anesthesiologist recorded the data.