Proposing an Endotracheal Tube Selection Tool Based on Multivariate Analysis of Airway Imaging

Abstract

Objectives: We aimed to comprehensively investigate different upper airway segments in adults, determine the predictors of the size of each segment, and identify an appropriate endotracheal tube (ETT) size chart. Study Design: Retrospective chart review. Setting: Tertiary care center. Materials and Methods: The data for patients aged >18 years who underwent neck computed tomography were screened. Patients with existing tumors, trauma, or any pathology that can alter the normal airway anatomy and those with intubation, tracheostomy, or nasogastric tubes were excluded. Computed tomography software was used to measure the anteroposterior diameter (APD), transverse diameter (TD), and cross-sectional area (CSA) at the glottic, proximal subglottic, distal subglottic, and tracheal levels. Multiple regression analysis was used to identify the predictors of the airway size. Results: One hundred patients were reviewed. The TD was consistently smaller than or equal to the APD at each level in all but 3 patients. The mean CSA and TD (170 mm2 and 11.3 mm, respectively) of the glottis indicated that the glottis was most often the narrowest level, followed by the proximal subglottis where the mean CSA and TD were 192.1 mm2 and 12.7 mm, respectively. Moreover, the mean APD was the smallest at the level of the trachea (20.1 mm). Multiple regression analysis confirmed that height and sex were the predominant predictors of measurements for the 4 airway segments. In addition, age was associated with the TD and CSA of the distal subglottic and tracheal segments, respectively. Conclusion: One-third of our participants exhibited a proximal subglottic diameter that was equal to or smaller than the glottic diameter. Our findings also suggested that the height and sex of the patients are important variables for the selection of an appropriate ETT size.

Application of B-ultrasound for localization and its impact on first-attempt success rates of nasogastric tube insertion in critically ill patients

“…[25–27] While the blind insertion method does not require specialized instruments, the human body’s complex anatomical structure lowers the success rate of catheterization, lengthens the time required for the tube to pass through the pylorus, and necessitates multiple X-ray exams to determine the catheter tip’s position. [28–30]…”

“…[25][26][27] While the blind insertion method does not require specialized instruments, the human body's complex anatomical structure lowers the success rate of catheterization, lengthens the time required for the tube to pass through the pylorus, and necessitates multiple X-ray exams to determine the catheter tip's position. [28][29][30] In this study, ultrasound-guided nasointestinal catheterization was utilized, combining ultrasonic positioning during catheterization to monitor the catheter tip's position in realtime. This improved the pyloric passing rate and overall success rate of catheterization.…”

Association between surgical tracheostomy and chronic tracheal stenosis: A retrospective, single-center study

“…In most reports regarding tracheostomy, bronchoscopy has been used to assess for tracheal stenosis ( 12 ). However, detailed changes in tracheal diameter by numerical value cannot be measured by bronchoscopy, and it is relatively invasive compared to CT ( 13 – 16 ). Thus, this is the first study to show detailed tracheal measurements over time in patients with asymptomatic tracheal stenosis after conventional surgical tracheostomy.…”

Endotracheal cuff undersizing diagnosed by computed tomography: Case report

“…Aljatlany et al 7 introduced the following formula for measuring the cross-sectional area of the trachea: Crosssectional area = −171.834 + (0.5850 × age in years) + (86.8685 × sex) + (2.3953 × height in cm), where sex is denoted by "1" for men and "0" for women). The final calculated tracheal cross-sectional area of the patient in the present case was 247.5734 mm 2 .…”