Chapter 58: Supraclavicular and Infraclavicular Nerve Blocks

SUPRACLAVICULAR NERVE BLOCK

Indications

The supraclavicular nerve block is ideal for pain of the upper extremity below the shoulder. The trunks formed by the C5-T1 nerve roots of the brachial plexus are very closely approximated at this level, so all the branches of the brachial plexus will be successfully blocked.

Anatomy

(Figure 58-1)

Brachial Plexus

• The nerve roots of the brachial plexus join to form the trunks.

• The C5 and C6 nerve roots (with occasional significant contributions from C4) combine to form the superior trunk.

• The C7 nerve roots become the middle trunk.

• C8 and T1 nerve roots (with occasional contribution from T2) form the inferior trunk.

• The 3 trunks emerge from the interscalene space and continue in an anterior, lateral, and inferior direction.

• The trunks converge near the upper surface of the first rib and as they cross the first rib around the upper border of the clavicle, they divide into their separate anterior and posterior divisions.

The relationship of the subclavian artery and vein:

• The relationship of the subclavian artery and vein (later the axillary artery and vein, respectively) to the trunks is an important consideration.

• When the subclavian artery passes under the clavicle, it becomes the axillary artery. Anatomically the subclavian artery (above the clavicle) lies in front of the trunks, while distally and below the clavicle at the level of the cords the axillary artery lies in the middle.

• The subclavian vein (above the clavicle) is separated from the subclavian artery by the anterior scalene insertion, and therefore does not travel within the neurovascular bundle (Figure 58-2).

• Distal to the clavicle, the axillary vein joins the neurovascular bundle, so that now the cords are found around the artery but also in between the axillary artery and vein.

Techniques

The supraclavicular nerve block can be performed with either a nerve stimulator or under ultrasound guidance. The complication most often associated with this block is a pneumothorax. Remember that the apex of the lung is just medial and posterior to the brachial plexus as well as ...