The changes of endotracheal tube intracuff pressures after ear and head and neck surgery-related positions: a prospective observational study

Abstract

IntroductionThe cuff of an endotracheal tube seals the airway to facilitate positive-pressure ventilation and reduce subglottic secretion aspiration. However, an increase or decrease in endotracheal tube intracuff pressure can lead to many morbidities. ObjectiveThe main purpose of this study is to investigate the effect of different head and neck positions on endotracheal tube intracuff pressure during ear and head and neck surgeries. MethodsA total of 90 patients undergoing elective right ear (Group 1: n=30), left ear (Group 2: n=30) or head and neck (Group 3: n=30) surgery were involved in the study. A standardized general anesthetic was given and cuffed endotracheal tubes by the assistance of video laryngoscope were placed in all patients. The pilot balloon of each endotracheal tube was connected to the pressure transducer and standard invasive pressure monitoring was set to measure intracuff pressure values continuously. The first intracuff pressure value was adjusted to 18.4mmHg (25cm H2O) at supine and neutral neck position. The patients then were given appropriate head and neck positions before related-surgery started. These positions were left rotation, right rotation and extension by under-shoulder pillow with left/right rotation for Groups 1, 2 and 3, respectively. The intracuff pressures were measured and noted after each position, at 15th, 30th, 60th, 90th minutes and before the extubation. If intracuff pressure deviated from the targeted value of 20–30cm H2O at anytime, it was set to 25cm H2O again. ResultsThe intracuff pressure values were increased from 25 to 26.73 (25–28.61) cm H2O after left neck rotation (p=0.009) and from 25 to 27.20 (25.52–28.67) cm H2O after right neck rotation (p=0.012) in Groups 1 and 2, respectively. In Group 3, intracuff pressure values at the neutral position, after extension by under-shoulder pillow and left or right rotation were 25, 29.41 (27.02–36.94) and 34.55 (28.43–37.31) cm H2O, respectively. There were significant differences between the neutral position and extension by under-shoulder pillow (p<0.001), and also between neutral position and rotation after extension (p<0.001). However, there was no statistically significant increase of intracuff pressure between extension by under-shoulder pillow and neck rotation after extension positions (p=0.033). ConclusionAccessing the continuous intracuff pressure value measurements before and during ear and head and neck surgeries is beneficial to avoid possible adverse effects/complications of surgical position-related pressure changes.