[Effects of topical anesthesia with 1% tetracaine on hemodynamic responses in microlaryngosurgery].

Objective: To observe the effects of topical anesthesia with 1% tetracaine on hemodynamic responses in general anesthesia patients undergoing microlaryngosurgery. Methods: From October 2021 to December 2021, 92 patients (46 males and 46 females) in Beijing Tongren Hospital, with a median age [M (Q1, Q3)] of 51 (42, 57) years who scheduled for microlaryngosurgery under general anesthesia, were divided into two groups (n=46 in each group) using the random number table method. Group T received topical anesthesia with 1% tetracaine at the root of the tongue and epiglottis and glottis on the basis of general intravenous anesthesia induction, with 0.5 ml at each position, while the control group (group C) received equal volume of normal saline. Heart rate (HR) and mean arterial pressure (MAP) were recorded at the time of patients entering the operating room (baseline), after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation. The recovery profiles, including time to recover breathing, time to open eyes, time to extubation and adverse reactions were evaluated during recovery period. Results: The MAP of patients in group T at baseline, after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation were (99.4±12.9), (78.5±8.8), (79.2±10.2), (100.6±17.0), (101.9±14.7), (100.8±13.9), (97.4±12.1), (107.3±16.8) mmHg (1 mmH=0.133 kPa), respectively, while in group C were (99.5±11.6), (80.9±12.8), (90.5±16.0), (109.5±20.4), (108.0±18.9), (103.7±15.5), (100.1±13.3), (114.2±17.3) mmHg, respectively. The two critical time points of MAP after intubation and immediately suspending laryngoscopy in group C were significantly higher than group T (P<0.05).The HR of patients in group T at baseline, after induction, after intubation, immediately after suspending laryngoscopy, 1 min after suspending laryngoscopy, 3 min after suspending laryngoscopy, 5 min after suspending laryngoscopy and immediately after extubation was (71.3±10.6), (66.0±10.1), (69.5±11.4), (61.3±14.2), (69.8±9.8), (71.0±10.6), (70.6±11.0), (78.8±11.6) bmp, respectively, while in group C were (73.1±10.9), (67.8±9.9), (79.5±12.9), (57.1±18.1), (69.2±12.8), (71.4±11.7), (70.7±11.5), (85.3±13.0) bmp, respectively. The two critical time points of HR after intubation and after extubation in group C were significantly higher than that of group T (P<0.05). The time to recover breathing in the two groups was (11.8±3.5) min and (11.3±4.6) min, respectively. The time to open eyes was (12.0±3.3) min and (11.5±5.0) min, respectively. The time to extubation was (13.2±3.7) min and (12.6±4.9) min, respectively. There were no statistically significant difference in time to recovery between the two groups (P>0.05). Likewise, there were no toxic reactions to local anesthetics, respiratory depression, hypoxemia, laryngospasm and cough occurred in either group. Conclusion: Topical anesthesia with 1% tetracaine can effectively reduce the hemodynamic changes without influencing patient's recovery, and does not increase the incidence of adverse reactions.