Topical Bupivacaine Effect On The Response To Awake Extubation During Emergence From General Anesthesia

* Emergence from general anesthesia is often complicated by the ETT-induced emergence phenomena (EP), which include coughing, sympathetic stimulation, sore throat, increased bleeding from the surgical site, and increased intracranial and intraocular pressures. * Techniques that have been used to help diminish coughing during emergence include "deep" extubation (removal of the endotracheal tube \[ETT\] while the patient is still in a deep plane of general anesthesia), administration of intravenous (IV) narcotics, or administration of IV lidocaine prior to emergence since systemic narcotics and lidocaine have antitussive properties. However, each of these techniques has limitations. A reliable technique for improving ETT tolerance while facilitating rapid and full emergence from general anesthesia would be desirable in many situations. * Topical application of bupivacaine to the pharyngeal, laryngeal, and tracheal mucosa will attenuate or even abolish coughing as well as a hemodynamic response during extubation, thus result in increasing the patient's comfort and avoiding potential complications of extubation process. * Up to the investigator's knowledge there is no study done to evaluate the effect of topical bupivacaine on the incidence of coughing and hemodynamic response during emergence from general anesthesia in patients undergoing elective thyroidectomy.