Patient Position: Supine, with the arm abducted at 90° to 110° at the shoulder and flexed 90° at the elbow.

Indications: Anesthesia and postoperative analgesia for surgery at the elbow and below (hand and forearm).

Needle Size: 22-gauge, 50-mm insulated needle.

Volume: 40 mL of a mixture of 0.5% ropivacaine and 1.5% mepivacaine v/v.

Anatomic Landmarks: Axillary artery in the middle portion of the axilla.

Approach and Technique: The axillary artery pulse is palpated and marked in the middle of the axilla. After disinfection, sterile draping, and local infiltration with 1% lidocaine, a 50-mm insulated needle connected to a nerve stimulator (1.5 mA, 2 Hz, 0.1 ms) is inserted above the artery, pointing in a proximal direction almost parallel to the artery at a 30° to 45° angle to the skin (Fig. 8-1A). After identification of a median nerve response (flexion of the fingers and the wrist) at a current below 0.5 mA, 15 mL of local anesthetic is injected slowly (10 mL/min) and in 5-mL increments. The 50-mm insulated needle is then withdrawn from the skin and redirected toward the coracobrachialis muscle (Fig. 8-1B). After identifying a musculocutaneous nerve response (biceps contraction, flexion of the elbow) at a current below 0.5 mA, 10 mL of local anesthetic is injected slowly (10 mL/min) and in 5-mL increments. The 50-mm insulated needle is then completely withdrawn and reinserted below the artery 45° to the skin and to the artery (Fig. 8-1C). After identification of a radial nerve response (extension of the fingers and the wrist) at a current below 0.5 mA, 15 mL of local anesthetic is injected in the same fashion as for the two other nerves. The
axillary block is completed by a subcutaneous infiltration at the medial aspect of the upper arm at a high humeral level to block intercostobrachial nerve fibers.

Patient Position: Supine, with the arm abducted at 90° and the forearm extended.

Indications: Surgery at or below the elbow.

Needle Size: 22-gauge, 50-mm b-beveled insulated needle.

Volume: 5 to 8 mL per nerve.

Anatomic Landmarks: Upper one-third of arm and the brachial artery. At the level of the brachial canal, the median, ulnar, radial, and musculocutaneous nerves are dispersed around the brachial artery (Fig. 8-2). The median nerve usually runs anterior and superior to the brachial artery, while the musculocutaneous nerve runs posterior and superior to the median nerve in a groove between the biceps and coracobrachialis muscle. The ulnar nerve runs medial to the brachial artery, and the radial nerve runs medial and posterior, between the triceps muscle and the medial border of the humerus. The closer to the elbow, the more separated are the nerves.

Approach and Technique: First, a line is drawn over the brachial artery. Then, a 22-gauge, 50-mm insulated needle connected to a nerve stimulator (2 mA, 2 Hz, 0.1 ms) is introduced almost tangentially to the skin, between the brachial artery and the palpating finger of the anesthesiologist, in the direction of the axilla in search of the median nerve. The stimulation of the median nerve (Fig. 8-3A) induces a contraction of the flexor carpi radialis and flexor digitorum superficialis of the fingers (flexion of the fingers). Once this response is obtained, the position of the needle is adjusted to maintain the same motor response with a current of 0.3 to 0.5 mA. Then, 8 mL of local anesthetic is injected slowly. Next, the needle is withdrawn to the skin, the current
is increased to 5 mA, and the needle is redirected in search of the ulnar nerve (Fig. 8-3B). The stimulation of the ulnar nerve induces a contraction of the flexor carpi ulnaris (flexion of the little finger and opposition of the little finger and thumb). Once this response is obtained, the position of the needle is adjusted to maintain the same motor response with a current of 0.3 to 0.5 mA. Then, 8 mL of local anesthetic is injected slowly. Next, the needle is withdrawn to the skin, the current is increased to 5 mA, and the needle is redirected in search of the radial nerve (Fig. 8-3C). The stimulation of the radial nerve induces a contraction of the extensor muscles, including the extensor radialis (extension of the fingers and especially the thumb). Once this response is obtained, the position of the needle is adjusted to maintain the same motor response with a current of 0.3 to 0.5 mA. Then, 8 mL of local anesthetic is injected slowly. To block the musculocutaneous nerve, the needle is withdrawn to the skin and reintroduced in a superior and posterior direction toward the coracobrachialis muscle. The stimulation of the musculocutaneous nerve (Fig. 8-3D) induces contraction of the biceps muscle (flexion of the forearm). Once this response is obtained, the position of the needle is adjusted to maintain the same motor response with a current of 0.3 to 0.5 mA (Fig. 8-4). Then, 5 mL of local anesthetic is injected slowly. After disconnection of the nerve stimulator, 3 mL of local anesthetic is injected subcutaneously medially and laterally to the brachial artery to block the medial cutaneous nerve of the arm and the medial cutaneous nerve of the forearm.