The Effect of Position Changing on Endotracheal Tube Cuff Pressure and Post-Operation Sore Throat and Hoarseness in Patients Undergoing General Anesthesia

Original Article Iranian Journal of Otorhinolaryngology, Vol.37(4), Serial No.141, Jul-2025 The Effect of Position Changing on Endotracheal Tube Cuff Pressure and Post-Operation Sore Throat and Hoarseness in Patients Undergoing General Anesthesia Masoomeh Tabari1 , Faezeh Rajabi1, Ali Moradi2,3, *Alireza Sharifian Attar1 Abstract Introduction: Endotracheal intubation is a standard procedure for securing and maintaining the airway during general anesthesia. Cuff pressure must be within the correct range to avoid serious airway complications. This study aimed to assess how the pressure in the endotracheal tube cuff changes when the patient’s position is altered. Materials and Methods: This prospective, observational study was conducted on 85 patients aged 18 to 75 undergoing general anesthesia for surgery. Endotracheal intubation was performed with an appropriately sized tube, and the tube cuff was inflated with air using a syringe. The cuff pressure of the endotracheal tube was then assessed using a cuff manometer immediately after intubation and position change, 5 minutes after each, and every 15 minutes until the end of the surgery. Based on the formula for testing the difference between two means for a quantitative trait in two populations, and considering an alpha of 0.05 and a beta of 0.2, the sample size was calculated as 20 individuals in each group of patients with different positions. Results: The endotracheal cuff pressure increased in all three positions, including prone, right lateral, and left lateral. A significant relationship was also observed between the sore throat one hour after extubation and the prone position. Conclusion: The ETT cuff pressure increased or decreased outside the normal range in most patients undergoing surgeries that require changing positions. Therefore, we recommend close and continuous monitoring of cuff pressure during anesthesia. Keywords: Endotracheal tube; Cuff pressure; position; Hoarseness; Sore Throat Received date: 29 Jan 2025 Accepted date: 21 Apr 2025 *Please cite this article; Tabari M, Rajabi F, Moradi A, Sharifian Attar AR. The Effect of Position changing on Endotracheal Tube Cuff Pressure and Post-operation Sore Throat and Hoarseness in Patients Undergoing General Anesthesia. Iran J Otorhinolaryngol. 2025:37(4):213-219. Doi: 10.22038/ijorl.2025.85571.3870 1Department of Anesthesiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Research Development Unit, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. 3 Orthopedic Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. 2Clinical Corresponding Author: Department of Anesthesiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran, E-mail: Copyright©2025 Mashhad University of Medical Sciences. This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 International License https://creativecommons.org/licenses/by-nc/4.0/deed.en 213 Tabari M, et al Introduction Endotracheal intubation is a standard procedure for securing and maintaining the airway during general anesthesia. The ideal endotracheal tube (ETT) cuff pressure is between 20 and 30 cmH2O (1). Over-inflation of the endotracheal cuff causes the pressure inside the cuff to surpass the capillary perfusion pressure of the tracheal mucosa (2). Tracheal hypoperfusion is associated with ischemia, stenosis, necrosis, ulceration, fistula, and respiratory complications such as cough, sore throat, and hoarseness (2,3). However, when the cuff pressure is too low, secretions may be inhaled into the lungs, resulting in ventilatorassociated pneumonia (4-6). The ETT cuff pressure is typically checked once right after intubation by palpating the pilot balloon or using a manometer (4). However, the ETT cuff pressure can change later due to factors like airway pressure and the patient's position during surgery (5, 6). Given the importance of the mentioned complications, regular monitoring of the endotracheal tube cuff pressure is essential. Some surgical procedures, such as nephrectomy and PCNL, involve adjusting the patient's position. The pressure on the ETT has been reported to be higher in the lateral compared to the neutral position (7). It has also been reported that changing from the supine to the prone position in lumbar spine surgeries alters the cuff pressure (8, 9). As a result, in surgeries that involve position changes, especially when the surgery times are long, the cuff pressure may be subjected to significant changes. According to the reviews, comprehensive studies examining cuff pressure at various positions and postoperative complications are lacking. We aimed to investigate the association between endotracheal tube cuff pressure, patient positions during surgery (prone, right and left lateral, and supine), and post-extubation complications, including hoarseness and sore throat, in patients undergoing urological, orthopedic, and general surgeries. approved by the University ethics committee (IR.MUMS.IRH.REC.1402.237). A written informed consent was obtained from all the patient participants. Eighty-five Patients aged 18 to 75 years undergoing urological, orthopedic, and general surgeries, in which the patient's position changed during the procedure, were evaluated. Each patient was initially monitored supinely using electrocardiography, blood pressure, and pulse oximetry. General anesthesia was then induced using a preoxygenation protocol with 100% oxygen, Midazolam, Sufentanil or Fentanyl, Propofol, and Cisatracurium. Endotracheal intubation was performed with an ETT sized 6.5/7 for females and 7.5/8 for males, and the tube cuff was inflated with air using a syringe. The ventilator was set to a volumecontrolled mode with a tidal volume of 6 cc/kg and a PEEP of 5 cmH2O. The ETT cuff pressure was assessed using a cuff manometer (VBM cuff pressure gauge with hook) immediately after intubation, position change, 5 minutes after each, and every 15 minutes until the end of the surgery. Although the ETT cuff pressure was constant during the operations, it was re-adjusted whenever it exceeded the normal range (20-30 cm H₂O). The sample size was calculated according to the outcomes of a similar study and considering an α=0.05 and a β+0.2, using the formula for comparing the means in two populations (8). The patients were also evaluated for hoarseness, sore throat, and cough an hour after the surgery. The patients scored sore throat using the visual analogue scale (VAS). Results The data from 85 patients were finally analyzed. Table 1 presents the characteristics of the study population, including the age, gender, Body Mass Index, airway physical exams, past medical history, ASA (American Society of Anesthesiologists Class: a risk-stratifying system used to help predict preoperative risks) classes, and ETT size and type. Materials and Methods This prospective, double-center, observational study w (...truncated)