Superior ulnar collateral artery Superior ulnar collateral artery The superior ulnar collateral artery (inferior profunda artery), of small size, arises from the brachial artery a little below the middle of the arm; it frequently springs from the upper part of the a. profunda brachii. It pierces the medial intermuscular septum, and descends on the surface of the medial head of the Triceps brachii to the space between the medial epicondyle and olecranon, accompanied by the ulnar nerve, and ends under the Flexor carpi ulnaris by anastomosing with the posterior ulnar recurrent, and inferior ulnar collateral. It sometimes sends a branch in front of the
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