cervical plexus block, anesthetic nerve block at any point below the mastoid process from the second cervical vertebra to the sixth cervical vertebra. This method is used for operations on the area between the jaw and clavicle, such as for carotid endarterectomy. Complications may include Horner’s syndrome, inadvertent stellate ganglion or brachial plexus block, vertebral artery bleeding or infection, subarachnoid or peridural penetration, phrenic nerve block or palsy manifested by respiratory failure, or laryngeal nerve block, manifested by sudden hoarseness.
