Case presentation

A right-hand dominant woman aged 46 years with a history of opiate use disorder presents to the ED following a right clavicle injury. While riding to work, the patient fell off her bicycle, landing on her right shoulder. She denies any other injury. On physical examination, she is tearful, cradling her right arm. Her vital signs are normal. Her right clavicle has an obvious deformity and associated bruising without overlying injury or tenting of the skin. She has severely reduced range of motion of the right shoulder due to pain but is neurovascularly intact distally. Plain radiography of her right clavicle (figure 1) revealed a comminuted right clavicular fracture with a coracoclavicular distance of 7 mm. Given her personal history with opioids, the patient declined narcotics but was in severe acute pain. Thus, the ultrasound machine was brought to the bedside in anticipation of ultrasound-guided regional anaesthesia of the superficial cervical plexus.

What is a superficial cervical plexus block?

The superficial cervical plexus block (SCPB) targets branches of the cervical plexus, specifically cervical nerve roots C2–C4. These branches emerge from the posterior aspect of the sternocleidomastoid muscle (SCM), about halfway between its origin on the manubrium and medial clavicle and its insertion on the mastoid process posterior to the ipsilateral ear as shown in figure 2.

The superficial cervical plexus provides anaesthesia to the skin from the inferior earlobe superiorly, the midline neck anteriorly, the lateral aspect of the trapezius laterally and along the clavicle inferiorly as shown in figure 3. There is no motor innervation by the …