Dexamethasone As a Bupivacaine Adjuvant for Ultrasound Guided Interscalene Brachial Plexus Block

Abstract

ain after orthopedic surgery can be intense. In particular, managing pain after shoulder procedures poses a challenge to both anesthesiologists and orthopedic surgeons. In an effort to improve analgesia and facilitate mobilization, regional anesthesia in the form of brachial plexus block through interscalene approach is often used either as an adjunct to general anesthesia or as the primary anesthetic. The brachial plexus of nerves arises from the ventral rami of C5 to T1 (with variable contributions from C4 and T2) and travels between the anterior and middle scalene muscles, ultimately providing sensory and motor innervation to the shoulder, arm, and hand. The upper elements of the plexus (innervating the shoulder and part of the arm) are more superficial and are readily accessible for deposition of local anesthetic in the interscalene area. Although associated with complications such as plexus injury, unintended spinal or epidural anesthesia, or intravascular injection, the actual rate of severe acute or long-term complications is only 0.4%. Use of an interscalene block as the primary anesthetic increases the proportion of patients suitable for PACU bypass and decreases immediate postoperative pain. However, the improved analgesia is short-lived: the block has not been shown to improve pain scores beyond 12 hours postoperatively.