The brachial plexus is derived from the cervical roots C5, C6, C7, C8 and the thoracic root T1. The plexus runs from the neck to the axilla passing between the clavicle and the first rib. In the axilla the plexus forms 3 cords which surround the axillary artery - the posterior, lateral and medial cords. The cords form the nerves to the arm - the median, ulnar, radial and the musculocutaneous nerve. Alongside the axillary artery runs the axillary vein.

Interscalene Brachial Plexus Block Supraclavicular(Subclavian)Brachial Plexus Block Infraclavicular Brachial Plexus Block Axillary Brachial Plexus Block

Forearm and hand surgery

The patient is positioned supine with the head turned 30 degree to the contralateral side. The interscalene groove is palpated at its most inferior point which is just posterior to the subclavian artery pulse, which can be felt just medial to the midpoint of the clavicle. Another technique is just measure the whole length of the clavicle and midpoint of the just above the clavicle is the point one needs for the supraclavicular approach.

After a skin wheal with local anesthesia, a 22-guage ,1.5 inch needle is directed just above and posterior to the subclavian Pulse and directed caudally against the skin. The needle is advanced until a paresthesia is encountered or muscle contraction of a forearm is noted. If the paresthesia or contraction is still observed ,then 25-40 ml of local anesthesia is injected. If the rib is encountered without a paresthesia or if blood is encountered, then the needle is withdrawn and the landmarks of the needle insertion path are reevaluated.

Phrenic nv and recurrent laryngeal nv blocked leading to respiratory failure and Horners syndrome with dyspnea and hoarseness of voice. Puncture of the pleura may cause Pneumothorax. Hemothorax. Hematoma and Infection. Chylothorax