Accuracy of ultrasonographic measurement of subglottic airway diameter in selecting cuffed endotracheal tube size for pediatric patients with congenital heart disease / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the accuracy of ultrasonographic measurement of the subglottic airway diameter in selecting the cuffed endotracheal tube (ETT) size for the pediatric patients with congenital heart disease.Methods Sixty pediatric patients of both sexes with congenital heart disease,of American Society of Anesthesiologists physical status Ⅱ-Ⅳ,aged 1 month-7 yr,undergoing elective open heart surgery,were included in this study.The subglottic airway diameter was measured by bedside ultrasonography after induction of anesthesia.The outer diameter of the cuffed ETT was determined according to the subglottic airway diameter.The air leak test was performed after intubation to determine whether or not the ETT size selected based on ultrasonography was appropriate.When the difference between the inner diameter of the finally selected ETT and the result calculated by the Motoyama formula was less than 0.2 mm,the ETT size selected based on the Motoyama formula was considered appropriate.The agreement and correlation between the subglottic airway diameter measured by age-based formula and ultrasonography and the outer diameter of the actually selected ETT were analyzed using Bland-Altman plot and Passing-Bablok regression analysis.Results The accurate rate of the ETT selected based on the ultrasonic measurement and Motoyama formula were 80％ and 55％,respectively,and there was significant difference (P＜0.05).Conclusion Ultrasonographic measurement of the subglottic airway diameter produces higher accuracy than the classical Motoyama formula in selecting the cuffed ETT size for the pediatric patients with congenital heart disease.