Infraclavicular Block

Clinical Applications

Infraclavicular block provides anesthesia to the arm and hand. Blockade occurs at the level of the cords and offers the theoretical advantages of avoiding pneumothorax while affording block of the musculocutaneous and axillary nerves. No special arm positioning is required. A nerve stimulator is required because there are no palpable vascular landmarks to aid in directing the needle.

Technique

The needle is inserted 2 cm below the midpoint of the inferior clavicular border and is advanced laterally, using a nerve stimulator to identify the plexus.^[18] Marking a line between the C6 tubercle and the axillary artery with the arm abducted is helpful in visualizing the course of the plexus. An incremental injection of 20 to 30 mL of solution is sufficient after the needle is correctly placed. A coracoid technique, with needle insertion site 2 cm medial and 2 cm caudal to the coracoid process, has also been described. ^[19] However, the more lateral insertion site may result in the absence of blockade of the musculocutaneous nerve, removing the major advantage of this approach over the simpler axillary block.

Side Effects and Complications

Because of the necessarily blind approach to the plexus, the risk of intravascular injection may be increased. Exaggerated medial needle direction may result in pneumothorax. Other rare complications such as infection and hematoma are theoretically possible.