Wrist Nerve Blocks

Used to provide anesthesia in distribution of median, ulnar, and/or radial nerves for the treatment of complex soft-tissue or bony injuries of the hand

Irrigation of deep abrasions with embedded debris

Extensive or complex laceration repair

Burn injury pain control

Incision and drainage of abscess

Fracture/dislocation reduction

Traumatic amputation

CONTRAINDICATIONS

Overlying cellulitis at site of anticipated injection

Relative Contraindications

Simple laceration or injury that can be easily and adequately anesthetized with local infiltration or digital block

COMPLICATIONS

Hematoma formation and/or vascular injury

Nerve injury

Infection

Allergic reaction

General Basic Steps

Palpate landmarks

Sterile prep of skin

Inject anesthetic

Consider sensory branches

ULNAR NERVE BLOCK

Landmarks

Flexor carpi ulnaris tendon, pisiform bone, ulnar artery, proximal wrist crease (FIGURE 82.1)

Ulnar nerve splits into dorsal and palmar branches approximately 5 cm proximal to the wrist crease

Palmar branch runs between the flexor carpi ulnaris tendon and the ulnar artery at the level of the proximal wrist crease

Technique

Patient Preparation

Place the hand comfortably on bedside procedure table with palmar surface up

Prepare wrist site in standard sterile manner (povidone–iodine solution or chlorhexidine)

Have patient flex wrist against resistance to accentuate landmarks

Identify and mark the flexor carpi ulnaris tendon from its insertion site at the pisiform bone to the ulnar nerve branch point (approximately 5 cm proximal to wrist crease)

FIGURE 82.1 Surface anatomy of the wrist region. (From Snell RS. Clinical Anatomy. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004:534, with permission.)

Injection

Approach the wrist medially and insert a small-bore (25-gauge) needle beneath the flexor carpi ulnaris tendon at the level of the proximal wrist crease (FIGURE 82.2)

Inject approximately 2 mL of anesthetic solution (lidocaine/bupivacaine) beneath the tendon at its radial border

Aspirate before injecting anesthetic to ensure that ulnar artery has not been inadvertently entered

To anesthetize the dorsal branch of the ulnar nerve use the same initial insertion site and technique. However, redirect needle 3 to 5 cm proximally toward the branch point.