Axillary Block Essay

o A key landmark when performing an axillary block is the identification of the axillary arterial pulse as well as the Coracobrachialis and pectoralis major muscle. o In supine position with the patient’s head turned away from the intended injection site, the desired arm is abducted 90° angle at the elbow joint. While standing at the upper arm, feel for the axillary artery (lateral to the pectoralis muscle) and draw a line along it from the mid-axilla to the lower axilla. This is helpful orientation for the longitudinal course of the artery. When trying to visualize the brachial plexus, it is imperative to know the nerve position in relation to the axillary artery pulse. For example, the median nerve lies superior to the pulse, the ulnar nerve
Using the non-palpating hand, inject local anesthetic subcutaneously into 4 outside quadrants around the pulse for skin paresthesia. A nerve stimulator initially set to deliver 0.5-1.0 mA should be connected to the stimulating needle. Begin insertion of a 22-gauge, short-bevel insulated stimulating needle below the axillary artery and perpendicular to the skin at a 45° angle cephalad. Slowly advance the needle 1 to 2 cm deep typically, until a radial nerve twitch (wrist or finger extension) is elicited. Aspirate and if negative, inject 10 to 15 mL of local anesthetic. Next, withdraw the needle and proceed with insertion above the artery. Gently advance the needle 1 to 2 cm until stimulating the median nerve (characterized by flexion of the finger) and continue slight advancement until the ulnar twitch reappears. Just like before, check for negative aspiration and then inject another 5 to-10 mL of local anesthetic. Withdraw the needle until reaching just below the skin site and redirect insertion up into the coracobrachialis towards the area of the musculocutaneous nerve. Advance the needle until the coracobrachialis twitch develops into a strong biceps brachii twitch and inject the remaining 5 to 8 mL of local