How would you block this?

38-year-old man was assaulted with a box-cutter resulting in a large laceration across the lateral aspect of his neck.  The laceration extended through the skin, subcutaneous fat, and superficial fascia revealing the underlying muscles and parotid gland.  CT/A of the neck showed no injury to the great vessels and the patient needs wound irrigation and closure.  With a single injection superficial cervical plexus block of 6mL 0.5 bupivacaine this patient had complete anesthesia.