Ultrasound-guided supraclavicular brachial plexus block is useful as a diagnostic maneuver to help identify if the brachial plexus is subserving pain from tumor, plexopathy, plexitis, abscess, or other pathology. Supraclavicular brachial plexus nerve block with local anesthetic may be used to palliate acute pain emergencies, including acute herpes zoster, brachial plexus neuritis, brachial plexopathy including Parsonage-Turner syndrome, upper extremity trauma, and cancer pain including Pancoast superior sulcus lung tumor, while waiting for pharmacologic, surgical, and antiblastic methods to become effective (Fig. 31.1). Supraclavicular brachial plexus nerve block is also useful as an alternative to stellate ganglion block when treating reflex sympathetic dystrophy of the shoulder and upper extremity. The use of ultrasound imaging can identify the exact location and course of the brachial plexus when surgical procedures of the neck and clavicle are being contemplated. For surgery of the upper extremity, supraclavicular brachial plexus block offers the dual advantages of rapid onset and dense surgical anesthesia. Destruction of the brachial plexus via the supraclavicular approach is indicated for the palliation of cancer pain, including invasive tumors of the brachial plexus as well as tumors of the soft tissue and bone of the upper extremity.

The fibers that comprise the brachial plexus arise primarily from the fusion of the anterior rami of the C5, C6, C7, C8, and T1 spinal nerves (Fig. 31.2). In some patients, there may also be a contribution of fibers from C4 to T2 spinal nerves. The nerves that make up the plexus exit the lateral aspect of the cervical spine and pass downward and laterally in conjunction with the subclavian artery. The nerves and artery run between the anterior scalene and middle scalene muscles, passing inferiorly behind the middle of the clavicle and above the top of the first rib to reach the axilla (Fig. 31.3). The scalene muscles are enclosed in an extension of prevertebral fascia, which helps contain drugs injected into this region and provide the theoretical and anatomic basis for this technique.

To perform ultrasound-guided injection technique for supraclavicular brachial plexus block, place the patient in the supine position with the head turned away from the side to be blocked. The posterior border of the sternocleidomastoid muscle is identified by having the patient raise

his or her head against the resistance of the clinician’s hand (Fig. 31.4). The point at which the lateral border of the sternocleidomastoid attaches to the clavicle is then identified (Fig. 31.5).