Comparison of Outside Versus Inside Brachial Plexus Sheath Injection for Ultrasound-Guided Interscalene Nerve Blocks

This report has been verified by one or more authors of the original publication.

60 patients undergoing elective shoulder surgery and receiving an interscalene nerve block were randomized to an injection of 0.5% ropivacaine either directly inside the brachial plexus sheath, or outside the brachial plexus sheath. The study was conducted in order to determine which administration method yielded a faster nerve block and to assess the side effects of each injection technique. It was found that injecting the local anesthetic into the brachial plexus sheath resulted in a faster nerve block onset; however, it also resulted in an increased incidence of transient paresthesia while positioning the needle, as compared to injecting outside the sheath. All other outcomes were comparable between groups.