In the transarterial technique for axillary brachial plexus block, the axillary artery is intentionally punctured to indicate placement of the needle within the neurovascular sheath; local anesthetic is then injected deep and superficial to the axillary artery.

To lessen the risk for hematoma and intravascular injection, several modifications, such as the multi-injection perineural technique, have become popular. These techniques require a high degree of technical skill and multiple needle passes, and also carry potential for injury. In this study, the investigators will compare an ultrasound-guided equivalent of the transarterial technique (periarterial injections) to a commonly used multi-injection perineural technique.

1. Inclusion criteria:

   - Patients (ASA physical status I-III) scheduled to undergo hand or wrist surgery under axillary brachial plexus block

2. Exclusion criteria:

   • Patients with pre-existing neuropathy
   • Patients with allergy to local anesthetics
   • Patients with prior surgery in the ipsilateral axilla
   • Pregnant patients
   • Patients with difficulties in communication