Prediction of the midtracheal level based on external anatomical landmarks: implication of the optimal insertion depth of endotracheal tubes in pediatric patients

Abstract

Optimal positioning of endotracheal tubes (ETTs) decreases the risk of accidental extubation or endobronchial intubation. This study evaluated the usefulness of external anatomical landmarks as practical references for determining an insertion depth of an ETT in pediatric patients. Computed tomography images of the necks of 183 pediatric patients (≤16 years of age) were reviewed. Levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified on sagittal reconstructed images. The surface measurements from the cricoid cartilage to the suprasternal notch and that from the suprasternal notch to the manubriosternal junction were determined. Bland-Altman analysis was used to interpret the relationship between the midtracheal level and the surface measurements. The difference between the midtracheal level and the surface distance from the cricoid cartilage to the suprasternal notch was 3.5 ± 7.0 mm, which was closer to zero than that between the midtracheal level and the surface distance from the suprasternal notch to the manubriosternal junction of 15.1 ± 6.1 mm. The midtracheal level, helpful in planning the insertion depth of an ETT, can be predicted by measuring the surface distance from the cricoid cartilage to suprasternal notch in pediatric patients.