Abstract
BACKGROUND: In the pediatric age group, age-based algorithms have been routinely utilized to determine the proper endotracheal tube (ETT) size for intubation. These algorithms frequently fall short of accurately predicting the ideal ETT size. The study's goal is to ascertain whether ultrasonography-derived tracheal internal diameter is a more accurate indicator of ETT size than age-based formulas. In the past, endotracheal tube size was determined using age-based calculations; however, more recently, ultrasound has been utilized to determine the subglottic diameter and select the proper endotracheal tube size. For anesthesiologists, assessing airways in children continues to be the most difficult assignment. The examination of a pediatric airway should now be accurate and informative thanks to recent advancements in ultrasound techniques.
AIM: To examine the accuracy of ultrasonography in determining the size of endotracheal tubes in pediatric patients and compare it with the age-based Motoyama formula for endotracheal tube outer diameter determination.
MATERIAL AND METHOD: Following the institutional ethical committee's clearance, sixty pediatric patients, age three to fourteen years who were scheduled for procedures under general anesthesia with endotracheal intubation and met the requirements ASA I & II, were added to the study. B-mode ultrasonography (USG) with excellent resolution was used to measure the subglottic diameter. The ETT that most closely matched the measured subglottic diameter in terms of OD was selected. The time required for USG scanning to measure the tracheal diameter in seconds, together with the clinically best fit ETT size and the actual ETT size used. The size of each patient's ETT was determined using the age-based Motoyama formula. A comparison was made between the ETT size estimated by USG and the age-based Motoyama formula before it was finally employed therapeutically.
RESULTS: Utilizing the age-based Motoyama formula, the mean endotracheal tube diameter was determined to be 2.66±0.62 mm. 7.1±1.12 mm was the mean subglottic diameter as determined by ultrasonography. 5.1±1.07 mm was the mean of the outside diameter that matched the subglottic diameter as determined by USG. The average ID value that matched the USG-measured OD was 3.12±0.69 mm. Each USG scanning took a total of 9.72±1.22 seconds, which was the meantime taken by USG.Based on the results of the air leak test, the mean of the clinically best-fit ETT was 5.15±0.68 mm. This figure is more than the mean of ETT size determined by the age-based Motoyama formula and nearly identical to the mean of ID corresponding to OD as determined by USG.
CONCLUSION: When compared to the age-based calculation, ultrasonography shown to be a reliable predictor for the assessment of the subglottic diameter of the airway in children in order to establish the appropriate endotracheal tube size for intubation. When choosing the right endotracheal tube size for clinical use, this non-invasive, safe method can help avoid patient trauma from repeated intubation attempts or inadequate ventilation. To further validate, though, larger-scale multicenter trials ought to be carried out.
KEYWORDS: Ultrasound imaging, Cricoid cartilageand Endotracheal intubation