Abstract: To explore the effects of bilateral superior laryngeal nerve block on preventing cardiovascular side-reactions under general anesthesia. Methods60 cases were randomly divided into two groups: the A and B groups. In the A group, both sides of the superior laryngeal nerve were blocked before general anesthesia, while in the B group, no treatment was performed before general anesthesia. The cardiovascular effects when the supporting-laryngoscope was placed and the tracheal catheter was extubated during the larynx micro-surgeries were evaluated. ResultsThe BP and HR levels were significantly decreased in the A group compared with the B group at three phases: the time when the supporting-laryngoscope was immediately placed; 5 minutes after the supporting-laryngoscope was placed; and 1 minute after the tracheal catheter was extubated(P<0.05). The cardiovascular side-effects in the B group were more serious than those before induction(P<0.05), also serious bradycardia was found. ConclusionsBilateral superior laryngeal nerve block can obviously suppress cardiovascular side-reactions of larynx micro-operations.

Key words: Larynx micro-operation, Cardiovascular reaction , Superior laryngeal nerve block