A brachial plexus block can be supplemented or "rescued" with a radial nerve block for surgeries in the distribution of the radial nerve or in the instance when a brachial plexus block may have spared the radial nerve distribution. The radial nerve is formed by fibers from C5-T1 spinal nerve roots and passes between the medial and the long heads of the triceps muscle, giving off a motor branch to the triceps and then inferiorly giving off sensory branches to the upper arm. At the level of the lateral epicondyle, between the lateral epicondyle and muscu-lospiral groove, the radial nerve divides into superficial and deep branches. The superficial branch gives sensory innervations to dorsum of the wrist, dorsal portion of index and middle fingers, and dorsal aspect of a portion to the thumb. Extensors of the forearm obtain most of the motor innervations from the deep branch of the radial nerve.
Arrange sterile towels, sterile gloves, gauze pads, marking pen, antiseptic solution, peripheral nerve stimulator, syringes, and needles for local infiltration and nerve block placement.
5-10 ml syringes of local anesthetic.
25 g 1.5 in. needle for skin infiltration.
3% chloroprocaine, 2% lidocaine, 0.5% ropivacaine, 0.5% bupivacaine.
Surface Anatomy and Landmarks Landmarks
Radial nerve block can be performed at the humerus (A), at the elbow (B), and at the wrist (C):
A. A point 3 in. above the lateral epicondyle of the humerus is identified on the muscu-lospiral groove between the heads of the triceps muscle. A 25 g 1.5 in. needle is inserted until a paraesthesia is elicited in the distribution of innervation of the radial nerve. When there is no persistent paresthesia, 7-10 cc of local anesthetic is injected following negative aspiration.
B. Lateral margin of biceps tendon at the crease of the elbow is identified. In a sterile fashion a 25 g 1.5 in. needle is inserted lateral to the biceps tendon at the crease and directed in a superior-medial direction. When a paresthesia is elicited and subsequent to negative aspiration, a total of 7-10 cc of local anesthetic is slowly injected.
C. With the patient in a supine position and operative arm adducted, identify the flexor carpi radialis tendon by asking the patient to flex the wrist. After aseptic preparation of the wrist, a 25 g 1.5 in. needle is inserted perpendicularly lateral to the flexor carpi radialis tendon, medial to the radial artery at the level of the distal radial prominence. Subsequent to eliciting a paresthesia, the needle is aspirated, and, when there is no persistent paresthesia and no blood to aspiration, a total of 3-4 cc of local anesthetic is injected.
Was this article helpful?
This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.