Ultrasonic Measurement of the Narrowest Transverse Diameter of Subglottic Airway in Children Undergoing Elective Tracheal Intubation under General Anesthesia

Backgroud: it was to study the application effect of ultrasonic measurement of the narrowest airway transverse diameter (TD) at the horizontal position of subglottic cricoid cartilage in the selection of endotracheal tube (ETT) in children with elective tracheal intubation (TI) under general anesthesia (GA). Methods: : 65 children undergoing elective TI under GA were enrolled as research objects, including 29 males and 21 females. There were 35 cases received uncuffed ETT while 30 cases adopted cuffed one. The type of ETTs was selected by ultrasonic measurement of TD of the subglottic airway and the age equation. The correlation between age, height, weight, subglottic airway TD and clinical optimal inner diameter (ID) of ETT was analyzed statistically. Results: : The accuracy of ultrasonic measurement method and age equation method with uncuffed ETT were 91.42% and 54.28%, respectively ( P <0.05). The accuracy with cuffed ETT turned out to be 86.66% and 36.66%, respectively ( P <0.05). There were correlations of age, height, weight, and subglottic airway TD with ID of the uncuffed or cuffed ETTs. The higher correlation was shown between subglottic airway TD and ID of ETT. Conclusion: The narrowest airway measurement by ultrasonography at the horizontal position of subglottic cricoid cartilage could be applied to evaluate the selection of uncuffed or cuffed ETT during TI under GA in children. This method was simple to operate, accurate, and worthy of clinical application significance.