OVERVIEW
This outpatient procedure numbs the arm and hand with an injection of local anesthetic. Typically, it is used before or after surgery on the elbow, forearm, or hand.

PREPARATION
The patient lies down to expose the armpit. The area is cleaned and sterilized, and a local anesthetic is administered to numb the tissue at the injection site.

LOCATING THE NERVES
The physician uses ultrasound or an electrical nerve stimulator to locate the brachial plexus nerves and the axillary artery, which pass through the upper arm. A needle is carefully guided through the armpit and down to the nerves.

NUMBING THE NERVES
Anesthetics are slowly injected through the needle, bathing the nerves and temporarily blocking sensation in the arm.