Nerve Block Anesthesia

Excerpt

The purpose of peripheral nerve blocks is to inhibit impulse transmission distally in a nerve terminal, thus terminating the pain signal perceived by the cortex. Nerve blocks can be used to treat acute pain (e.g., procedural anesthesia and perioperative analgesia), as well as for diagnosis and treatment of chronic pain. Impulse blockade can be brief (hours) or prolonged (months), depending on the medication used in the block and the technique (e.g., single-shot block versus catheter). Nerve blocks are also useful in the emergency department for the following indications: Acute pain management of the extremities.

1. Anesthesia of the extremity for procedures

2. Alternative to procedural sedation

3. Alternative to opioids in certain patient populations (e.g., a head injury patient, patients with concomitant mental status change, patients on buprenorphine)

Many nerves can be blocked depending on the injury. These include the following upper or lower extremities:

1. Brachial plexus roots at the interscalene location block the shoulder, upper arm, elbow, and forearm.

2. Brachial plexus trunks at the supraclavicular location block the upper arm, elbow, wrist, and hand.

3. Brachial plexus cords at the infraclavicular location block the upper arm, elbow, wrist, and hand.

4. Brachial plexus branches at the axillary location block the forearm, wrist, hand, and elbow, including the musculocutaneous nerve.

5. The median nerve at the elbow blocks the hand and forearm.

6. The radial nerve at the elbow blocks the hand and forearm.

7. The ulnar nerve at the elbow blocks the hand and forearm.

8. The femoral nerve at the femoral crease blocks the anterior thigh, femur, knee, and skin anesthesia over the medial aspect of the leg below the knee.

9. The sciatic nerve at the subgluteal location or anterior approach below the femoral crease blocks the posterior aspect of the thigh and the anterior, lateral, and posterior lower leg, ankle, and foot.

10. The sciatic nerve at the popliteal location blocks the anterior, lateral, and posterior lower leg, ankle, and foot.

11. Ankle block of five separate nerves to the ankle and foot (saphenous nerve, deep peroneal nerve, superficial peroneal nerve, posterior tibial nerve, and sural nerve) blocks the entire foot.