cervical plexus block

INTRODUCTION

The cervical plexus block provides anesthesia

and analgesia to the head and neck region.

Depending on the type of surgery, the plexus can

be blocked either at a superficial or a deep level.

The superficial branches (Figure 6-1) of the plexus

innervate the skin and superficial structures of

(Figure 6-2) innervate the muscles of the deep

anterior neck and the diaphragm. The deep cervical

plexus block is used for deeper surgeries of the

neck, such as carotid artery or thyroid surgery, and

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ANATOMY

The cervical plexus is formed from the anterior

rami of the C1 through C4 nerve roots; it lies

the sternocleidomastoid muscle. There are five main

components of the cervical plexus: (1) the cutaneous

branches, which supply the lesser occipital, greater

auricular, transverse cervical, and supraclavicular

nerves; (2) the ansa cervicalis, which innervates the

infrahyoid and geniohyoid muscles; (3) the phrenic

nerve, which is the only motor nerve to innervate

the diaphragm; (4) contributions to the accessory

nerve (CN XI), which innervates the sternocleidomastoid

and trapezius muscles; and (5) direct

muscular branches, which supply prevertebral

muscles of the neck.

would result in total diaphragmatic paresis, should

not be performed. Also, patients with chronic respiratory

conditions may not be suitable candidates for

an ipsilateral deep cervical plexus block. Caution

must be taken when placing a deep cervical plexus

block because of the close proximity of the vertebral

close to the vertebral artery may result in an intravascular

injection; placing it too close to the dural

sleeve may result in a subarachnoid injection.

perficial cutaneous surgeries of the head and neck.

This block is also useful as a supplement to other

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6

PROCEDURE

Landmarks

Superficial Cervical Plexus

 Identify and mark the posterior border of the sternocleidomastoid,

as well as the midpoint of the muscle.

Deep Cervical Plexus

Position the patient supine with the head turned toward the

nonoperative side. Palpate the transverse process

of C6 (Chassaignac’s tubercle) at the level of the

cricoid cartilage. Palpate the mastoid process

behind the ear. Draw a line between the mastoid

process and Chassaignac’s tubercle. The transverse

processes of the other cervical vertebrae

will lie on or near this line. The first palpable

transverse process below the mastoid process is

C2. Palpate and mark the transverse processes of

C2 to C4 (the C4 transverse process lies approximately

at the level of the mandible). Insert the needle medially and caudally so that the needle tip is resting on the transverse process.

• 22-gauge, 5-cm, short bevel needle.

Injection

Superficial Cervical Plexus

Insert the needle at the midpoint of the posterior border of the sternocleidomastoid muscle to approximately half the depth of the muscle, and inject 3 to 4 mL of local anesthetic.

Also perform a subcutaneous injection of additional

local anesthetic cephalad and caudad along the

length of the sternocleidomastoid muscle posterior

border.

Deep Cervical Plexus

. Attach a 10-mL control syringe to the needle. Once the transverse process is contacted, withdraw the needle 1

to 2 mm. Inject the local anesthetic slowly with frequent aspirations.

After completing the injection, remove the needle

and repeat the block at the next level. (Many institutions

perform only a superficial cervical plexus block, and the

surgeon infiltrates deeper structures as required.)

Local Anesthetic

Superficial Cervical Plexus

 5–10 mL.

Deep Cervical Plexus

 3–5 mL at  each level or 15 mL at C3 only.

Needles

regional techniques of the upper torso.

artery and the dural sleeve. Placing the block too

Bilateral deep cervical plexus blocks, which

anterior to the cervical vertebrae and posterior to

the superficial cervical plexus block is used for su

the head, neck, and shoulder. The deep branches