Discussion
coughing, postoperative cough, anxiety, coughing, laryngeal injury, postoperative cough and sore, throat, cough, agitation, airway complications, DBP increase, bladder irritation, postoperative sore throat, cough reaction, postoperative pharyngeal pain
BLADDER IRRITATION
The current study compared the application of compound lidocaine/prilocaine cream, tetracaine spray or compound lidocaine/prilocaine cream combined with tetracaine to the front end of the surface of the tracheal tube and demonstrated a significant reduction in the incidence of induced coughing, agitation caused by sputum aspiration and extubation and the active extubation rate, which suggest significantly improved tolerance to the tracheal tube in patients during emergence from general anaesthesia. At least 65.1% and 75.0% of patients had induced coughing in the lidocaine/prilocaine cream and tetracaine group, respectively. However, the incidence of induced coughing was significantly reduced to 22.2% by the combination of compound lidocaine/prilocaine cream with tetracaine. The incidence of emergence agitation and active extubation rate were also significantly reduced to 16.7% and 5.6% in the compound lidocaine/prilocaine cream combined with tetracaine group, respectively. Compound lidocaine/prilocaine cream combined with tetracaine was also the most effective method to prevent extubation-induced increases in SBP, DBP, HR, E and NE plasma concentrations in patients emerging from general anaesthesia. These findings demonstrated that compound lidocaine/prilocaine cream combined with tetracaine had a better airway surface anaesthesia effect and significantly increased tolerance to the tracheal tube in patients under general anaesthesia.Endotracheal intubation-related mechanical stimulation is clinically common and associated with airway complications including, severe coughing, laryngeal injury and postoperative sore throat [During emergence from general anaesthesia, sputum aspiration and tracheal tube extubation are the strongest stimulators of the tracheal mucosa, which is the most likely to induce cough. Our study showed that compound lidocaine/prilocaine cream combined with tetracaine significantly reduced the incidence of induced coughing caused by sputum suction and extubation by approximately 39% compared to the use of lidocaine/prilocaine cream alone. Although the spraying of tetracaine alone also significantly reduced the incidence of cough, the reaction was lowest in the lidocaine/prilocaine cream combined with tetracaine group. One systematic review and meta-analysis of dexmedetomidine, remifentanil, fentanyl, lidocaine i.v., intracuff lidocaine, and lidocaine via tracheal or topical route, demonstrated that in pair-wise comparisons all study medications were equivalent in reducing moderate and severe emergence coughing incidence, and were better than placebo or nothing [During emergence from general anaesthesia, the patient may exhibit emergence agitation. The main factor of emergence agitation is delayed extubation. Study showed that patients with delayed extubation developed a cough reaction was 16.7 times higher than patients without delayed extubation [Therefore, we though that compound lidocaine/prilocaine cream combined with tetracaine inhibited the airway reflexes caused by the tracheal tube and further enhanced the body's tolerance to the tube. Our results showed that compound lidocaine/prilocaine cream or tetracaine significantly improved tracheal tube tolerance. The tracheal tube tolerance scores were reduced to 2 (0, 1) and 3 (0, 1.25), respectively. Compound lidocaine/prilocaine cream combined with tetracaine further significantly increased tracheal tube tolerance, and the tracheal tube tolerance score was reduced to 1 (0, 0). Study showed that remifentanil 0.025–0.05 microg.kg(-1).min(-1) achieves satisfactory tracheal tube tolerance in awake and spontaneously breathing patients performed under general anaesthesia, the respiratory response subscore of comfort scale of patients is all 3 [These findings may induce beneficial effects on cardiovascular reactions during the course of extubation. The current study found that hemodynamic changes (blood pressure and/or HR) exceeded 20% of the baseline at 1 min after extubation. Compound lidocaine/prilocaine cream or tetracaine significantly reduced the SBP increase from baseline (△SBP), the DBP increase from baseline (△DBP) and the HR increase from baseline (△HR) about 8% ~ 12% compared to the use saline. However, compound lidocaine/prilocaine cream combined with tetracaine significantly reduced the average values of △SBP, △DBP and △HR about 30% ~ 50% compared to the use saline.When the endotracheal tube is removed, this stimulates the receptors of the airway mucosa, which results in the release of catecholamines [We also assessed the incidence of postoperative cough and postoperative pharyngeal pain. We found that the use of local anaesthetic significantly reduced these incidences compared to saline. The incidence of postoperative cough in the compound lidocaine/prilocaine cream (13.5%), tetracaine (21.2%) and compound lidocaine/prilocaine cream combined with tetracaine (13.0%) groups were not significantly different from each other. However, the incidence of postoperative pharyngeal pain was higher in the tetracaine group than in the compound lidocaine/prilocaine cream combined with tetracaine group. Soltani, H.A. and O. Aghadavoudi suggested that the use of lidocaine to inflate the endotracheal tube cuff at the end of surgery decreased the frequency of postoperative cough and sore throat by approximately 41.4% and 17.7% respectively, compared to the use of saline to inflate the endotracheal tube cuff [There are some potential risks in the application of local anaesthetics to the airway of a patient who is under general anaesthesia: 1) if the operation time is too long, the effect of the local anaesthetic will insufficient to suppress the cough response caused by extubation; 2) the local anaesthetic effects may extend to block part of the vocal cords and affect vocalisation; 3) compound lidocaine includes prilocaine, although we used safe doses, prilocaine may increase blood methemoglobin levels, which should be monitored in clinical practice.And there are some limitations to our study. 1) This study did not observe the duration of the continuous effect of compound lidocaine combined with tetracaine on airway topical anaesthesia. 2) This study did not consider the patient's anxiety state, which will affect the release of catecholamines during awakening, and may affect the evaluation of catecholamines released during tracheal tube extubation. 3) During recovery from general anaesthesia, the patient exhibits emergence agitation due to poor tolerance to the tracheal tube, which could not be well revealed in this study based on other factors, such as preoperative anxiety or bladder irritation caused by urine retention.