Median nerve and medial cords of the brachial plexus, courses through the anterior part of arm, forearm, and hand, and terminates by supplying the muscles of the hand. After receiving inputs from both the lateral and medial cords of the brachial plexus, the median nerve enters the arm from the axilla at the inferior margin of the teres major muscle. It then passes vertically down and courses lateral to the brachial artery between biceps brachii (above) and brachialis (below). At first, it is lateral to the artery and lies anterior to the elbow joint; it then crosses anteriorly to run medial to
Brachial plexus block collapse. In severe cases, cardiac dysrhythmia, cardiac arrest and death may occur. Other rare but serious complications from brachial plexus block include pneumothorax and persistent paresis of the phrenic nerve. Complications associated with interscalene and supraclavicular blocks include inadvertent subarachnoid or epidural injection of local anesthetic, which can result in respiratory failure. Because of the close proximity of the lung to the brachial plexus at the level of the clavicle, the complication most often associated with this block is pneumothorax — with a risk as high as 6.1%. Further complications of supraclavicular block include subclavian artery puncture, and spread of