Application of ultrasound in predicting difficult laryngoscopy in children / 临床麻醉学杂志

ABSTRACT

Objective To compare the effect of ultrasound measurements of the distance from skin to vocal folds (DSV), neck diameter (d) and the ratio among the two measurements (R) used to predict difficult laryngoscopy. Methods Seventy-two toddelers scheduled to undergo general anesthesia, aged ≤ 3 years, falling into ASA physical status Ⅰ or Ⅱ, were included and categorized as having easy (n = 48, grades Ⅰ and Ⅱ) or difficult (n = 24, grades Ⅲ and Ⅳ) laryngoscopy based on the criteria of Cormack and Lehane. When children were ventilated by mask, we measured DSV by ultrasound; obtained d and R. Receiver operating characteristic (ROC) curve analysis was used to determine the DSV, d and R in predicting difficult laryngoscopy. The value of cutoff was obtained by maximizing the Youden's index. Results DSV was significantly shorter in difficult laryngoscopy group (P ＜ 0.05). The areas under the ROC curve of R was 0.807, and the cutoff value was 0.090. the sensitivity was 70.83％, the specificity was 83.33％ Conclusion The ratio of distance from skin to vocal folds to neck diameter is a good predictor of difficult laryngoscopy in children under 3 years old.