Effect of Topical Anesthesia on Hemodynamics During the Induction Period in Patients Undergo Cardiac Surgery.

The superior glottic mucosa would be anesthetized 3 times with a vaporizer before intravenous anesthesia. After the intravenous induction, a catheter would be inserted to provide the subglottic anesthesia，3-5ml 2% lidocaine would be used for supraglottic anesthesia, and 3ml 1% tetracaine would be used for subglottic anesthesia.