The effect of different endotracheal tube cuff pressure monitoring systems on postoperative sore throat in patients undergoing tracheal intubation: a randomized clinical trial

BACKGROUND: Postoperative sore throat (POST) is an unpleasant outcome that can occur as a result of tracheal intubation in adults. Increased pressure from the endotracheal tube (ETT) cuff often leads to local mucosal injury, resulting in sore throat. The purpose of this study was to compare the effect of two different ETT cuff pressure monitoring systems vs. no cuff pressure monitoring on the incidence and severity of POST in adults. METHODS: One hundred and fourteen ASA I-III patients of either gender, aged 18-65 years, and undergoing surgery requiring endotracheal intubation were included in this study. Patients were randomized into three groups: control (C), cuff pressure gauge (G), and automated cuff controller (A). The ETT cuff pressure was not monitored intraoperatively in group C but was monitored using a cuff pressure gauge and an automated cuff controller in groups G and A, respectively. Postoperatively, patients were assessed at 2, 24, and 48 h for the presence and severity of POST, hoarseness and cough. RESULTS: One hundred and eleven patients completed the study. POST occurred in 40.5% of the patients in group G (n = 37) (p = 0.013) and 23.7% of the patients in group A (n = 38) (p < 0.001) within 48 h after surgery, compared to 69.4% in group C (n = 36). There were no significant differences in hoarseness, coughing, and dysphagia across the groups at any time. When comparing groups A and C, individuals in group A exhibited a lower occurrence of significant (grade ≥ 2) POST and hoarseness (10.5% vs. 41.7%, p = 0.002; 26.3% vs. 58.3%, p = 0.005). The incidence of significant cough and dysphagia did not differ substantially across the patient groups within 48 h after surgery. POST scores in group A at 2, 24 h postoperatively were both 0 (0-0), which was significantly lower than those in group C (1 (0-2) at 2 h, p < 0.001 ; 1 (0-1) at 24 h, p = 0.001). POST in group G at 2 h postoperatively was graded as 0 (0-1.5) which was milder than group C (P = 0.024). The severity of hoarseness in group A with scores of 0 (0-2) was superior to that in group C (2 (0-2), p = 0.006) at 2 h postoperatively. CONCLUSIONS: In conclusion, the findings of this study indicated that the occurrence of POST can be reduced by using either the cuff pressure gauge approach or the automated cuff controller method. The automated cuff controller monitoring can potentially decrease the severity of POST and hoarseness. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100054089, Date: 08/12/2021.