Minimum Effective Local Anesthetic Volume of 0.5% Levobupivacaine Required for Ultrasound Guided Superior Trunk Block for Shoulder Surgery

What this Trial Is About

Researchers are studying the minimum effective dose of levobupivacaine, a common local anesthetic, needed to provide effective pain relief through an ultrasound-guided superior trunk block for shoulder arthroscopic surgeries. This approach aims to reduce the risk of hemi-diaphragmatic palsy that can occur with the currently used interscalene brachial plexus block, by targeting the superior trunk of the brachial plexus where most shoulder innervation occurs. The study focuses on achieving effective anesthesia in at least 90% of patients. In this study, participants scheduled for shoulder surgery will receive an ultrasound-guided superior trunk nerve block with 0.5% levobupivacaine. The initial dose is 8 ml, which may be adjusted up or down by 2 ml for subsequent patients depending on the success of the block, with a maximum dose of 16 ml and a minimum of 4 ml. This dose-finding method uses the Modified Narayana rule to determine the minimum effective volume. Participants will be monitored for sensory and motor block changes of the upper extremity at 5-minute intervals for 45 minutes after the block to assess readiness for surgery. The study will also evaluate diaphragmatic function before and 30 minutes after the block, block performance time, discomfort scores, and any complications or paresthesia during the procedure. The aim is to find the lowest dose that provides effective anesthesia with minimal side effects during shoulder arthroscopic surgery.

Minimum Effective Local Anesthetic Volume for Ultrasound Guided Superior Trunk Block