All that follows is from the above resource.
Continuing Education Activity
Superficial cervical plexus block is an easy block that can be performed either using a landmark-based technique or using the ultrasound-based technique. This activity outlines the practical use of superficial cervical plexus block as performed by the bedside clinician in improving the care for patients presenting to the operating room or to the emergency department who require regional anesthesia. This activity review the clinical significance, technique, and potential complications of the procedure to enhance the delivery of this procedure and to improve outcomes.
Regional anesthesia can be part of a multi-model treatment plan to mitigate pain for clinical scenarios frequently seen in an emergency department and in the perioperative setting. Preoperatively, these blocks can be employed for a variety of surgical procedures. In the emergency department, it can be utilized for insertion of internal jugular central venous catheters, treatment of clavicular fractures and repairing lacerations, and draining abscesses that involve the earlobe and submandibular areas. The superficial cervical plexus block provides ipsilateral anesthesia to the “cape” region roughly bordered by the posterior tip of the earlobe, the lateral end of the clavicle, the medial aspect of the mandible and the inferior surface of the clavicle. Cervical plexus blocks are easy to perform and provide anesthesia for the surgical procedure in the distribution of C2 to C4, including carotid endarterectomies, lymph node dissection, and plastic surgery. The superficial cervical plexus block can also be used in combination with the deep cervical plexus block for regional anesthesia in oral and maxillofacial surgery.
Anatomy and Physiology
The superficial cervical plexus has its origins from the ventral rami of the nerve roots C2 to C4. These nerve roots provide sensation to the skin and superficial structures of the ear auricle, acromioclavicular joint, clavicle, and anterolateral neck. These branches exit at a midpoint along the posterior border of the sternocleidomastoid muscle (SCM) at the same level as the thyroid cartilage notch. These roots combine to form the four terminal branches, namely the lesser occipital, greater auricular, transverse cervical, and supraclavicular nerves. They emerge from behind the posterior border of the SCM. The plexus can be visualized as a small collection of hypoechoic oval structure, deep or lateral to the posterior border of the SCM, but this is not always apparent. The goal of this block is to deposit local anesthetic near the sensory branches of nerve roots C2, C3, and C4. SCM forms a “roof” over the nerve roots of the superficial cervical plexus (C2–4). The advantages of ultrasound guidance include visualization of the spread of local anesthetic and continuous monitoring of needle tip depth. While this paper provides sufficient anatomical information to perform a superficial cervical plexus block, there are other resources available for those interested in pursuing a more detailed review of the sonoanatomy of the cervical region.
A superficial cervical plexus block is indicated when there is a need for dense anesthesia and/or analgesia to the skin and underlying anatomy of the anterolateral neck. In addition to the anterolateral neck, anesthesia is achieved in the superficial structures of the ear, clavicle and the acromioclavicular joint. Common indications for superficial cervical plexus block include carotid endarterectomies, lymph node dissections, and superficial neck surgeries. In the emergency department, it can be utilized for insertion of internal jugular central venous catheters, treatment of clavicular fractures and repairing lacerations, and draining abscesses that involve the earlobe and submandibular areas. While there are no other published studies available, a single case series showed this block to be successfully used in pediatric patients requiring internal jugular venous placement for emergent dialysis.
Contraindications for superficial cervical plexus block include patient refusal, active infection overlying the injection site, contralateral phrenic nerve paralysis, previous neck surgery, neck radiation, and allergy to both amide and ester local anesthetic agents. Caution must be exercised in patients who suffer from severe chronic obstructive pulmonary disease or an untreated contralateral pneumothorax as this block has the potential for inadvertent phrenic nerve dysfunction. This potential complication, however, has been recently challenged by a recent prospective randomized study.