Compound Lidocaine cream combined with tetracaine prevents cough reaction of patients with general anesthesia caused by extubation: a randomised controlled trial
Authors: zhang Erfei , Zhao Xiaoying , Li Ting , Wang Min , gao Jie , Zhang Hailiang , li Ying , Zhang Lei , Li Taiyang 
Published: June 2022

Abstract
Background: Coughing response caused by tracheal extubation is the most common in general anesthesia patients with tracheal intubation during recovery from anesthesia. However, high aerosol production by coughing during recovery from general anesthesia in patients with respiratory infections (especially COVID-19) is one of the highest risk factors for infection among healthcare workers. Application of local anesthetics to the endotracheal tube is an effective method to reduce the choking reaction. The most commonly used anaesthetics are compound Lidocaine cream and tetracaine injection. However, there is still a certain number of choking reactions in the clinic when the two anaesthetics are used alone. We speculate that the combined application of compound Lidocaine cream and tetracaine will play a better role in prevent coughing response caused by tracheal extubation.Methods: A total of 211 patients, who had undergone laparoscopic cholecystectomy or cholecystectomy combined with common bile duct exploration under general anesthesia, were randomly assigned to Group C (saline injection, 53 cases), Group L(compound lidocaine cream, 52 cases), Group T (tetracaine, 52 cases) and Group F (compound lidocaine cream combined tetracaine, 54 cases). Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), levels of epinephrine and levels of norepinephrine were recorded or measured immediately before extubation and one minute after extubation. In addition, endotracheal tube tolerance, the incidence of bucking, the incidence of agitation, the active extubation rate, the incidence of postoperative pharyngeal pain and the incidence of postoperative cough were analyzed. Results: Blood pressure and heart rate as well as blood concentrations of epinephrine and norepinephrine were significantly higher in the group C compared with the every other group at the time of extubation as well as 1 min after extubation (P < 0.001). And group F significantly reduced the Blood pressure and heart rate as well as blood concentrations of epinephrine and norepinephrine compared group L or group T (P < 0.05, P < 0.01 or P < 0.001). When the patients emerged from general anesthesia, 96% of the group C had cough caused by sputum aspiration and extubation, which was significantly reduced by group L (61.5%, P < 0.001), group T (75%, P < 0.05) and group F (22.2%, P < 0.001), furthermore, group F significantly reduced the incidence of cough compared group L or group T (P < 0.01). Assessment of endotracheal tube tolerance, the score in the group C ((1, 3) 4, P < 0.001) is higher than group L ((0, 1) 2), group T ((0, 1.25) 3) and group F ((0, 0) 1), furthermore, group F significantly reduced the score compared group L or group T (P < 0.05, P < 0.01, respectively). The incidence of agitation and the active extubation rate were also higher in group C (96.2%, 71.7%, respectively, P < 0.001) than group L (48.1%, 15.4%, respectively), group T (61.5%, 26.9%，respectively) and group F (17.3%, 7.7%，respectively), furthermore，group F significantly reduced the incidence of cough compared group L or group T (P < 0.05 or P < 0.01). In addition, the incidence of postoperative pharyngeal pain and the incidence of postoperative cough were no statistical difference between every groupConclusions: Compound Lidocaine cream combined tetracaine may be a more advantageous approach for preventing choking and stabilizing circulation during extubation in emergence from general anesthesia, which may play an important role in preventing medical staff from contracting respiratory infectious diseases. Trial registration: Chinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09-04-2020) “retrospectively registered”.