Postoperative Vocal Cord Paralysis

You are scheduled to anesthetize a 65-yr-old woman (American Society of Anesthesiologists physical status 2) for a left carotid endarterectomy (CEA). She has hypertension, which is well controlled medically. Her past surgical history is significant for a thyroidectomy 17 yr ago. Otherwise she is well, with no known allergies. Her physical exam is normal and she has no stridor or hoarseness. She prefers to be awake for the surgery, and you do a deep and superficial cervical plexus block with 1.5% lidocaine with 1:200,000 epinephrine. Six milliliters is injected at C3, C4, and C5, while 14 ml is injected into the superficial plexus. The surgery starts with the patient awake, as she has only received midazolam 2 mg and 50 μg of fentanyl for the block. After a Pilling retractor is inserted, pushing the internal jugular vein and sternocleidomastoid laterally and the thyroid and trachea medially, the patient coughs repeatedly. The surgeon injects 6 ml of plain lidocaine 1% around the common carotid artery, but this does not help as the patient now develops stridor and becomes agitated. The retractor is removed and within a few minutes she feels much better. The surgeon inserts the retractor again, but once again the patient develops severe coughing and stridors. The patient is told that a general anesthesia is needed and she reluctantly agrees. She is anesthetized without any problems with fentanyl 200 ug, etomidate 18 mg, and vecuronium 7 mg. She is easy to mask ventilate. You have a grade 1 view, and your resident does note that the right vocal cord seem closer to the midline than the left. You have a look and agree with his assessment. An endotracheal tube (ETT) is placed uneventfully. The anesthetic is maintained with oxygennitrous-isoflurane. The surgery is completed uneventfully and a special note is made by the surgeon that the vagus nerve is intact. There is no evidence of a nonrecurrent laryngeal nerve. The recurrent laryngeal nerve is not seen