Original ArticleAccuracy of a Chest X-Ray-Based Method for Predicting the Depth of Insertion of Endotracheal Tubes in Pediatric Patients Undergoing Cardiac Surgery

ObjectivesThe incidence of endotracheal tube (ETT) malposition in children with various described methods is 15% to 30%. Chest x-ray (CXR) is the gold standard for confirming appropriate ETT position. The aim of this study was to measure the accuracy of a preoperative CXR-based method in determining depth of insertion of ETTs and to compare it with methods based on the intubation depth mark or formulae (age, height, and ETT internal diameter) in children undergoing cardiac surgery.DesignProspective observational study.SettingUniversity-affiliated tertiary care hospital.ParticipantsSixty-six consecutive children scheduled for elective pediatric cardiac surgery.InterventionsNone.Measurements and Main ResultsThe distance from carina to mid-trachea was measured for each child preoperatively on the CXR displayed as a computed radiography image in a picture archival and communications system computer. Following intubation, ETTs deliberately were pushed endobronchially and then pulled back to the carina; they were further withdrawn by the previously measured carina to mid-tracheal distance and secured. CXRs postoperatively were repeated to confirm ETT position. The ETT position was measured with other methods using the picture archival and communications system ruler on the postoperative CXR and compared with the CXR method. The proportion of appropriate ETT position with the CXR method was 98.5% (p≤0.001 v other methods). In children younger than 3 years, the appropriate proportion was 97.4%.ConclusionThe appropriate positioning of ETTs in the trachea by the CXR method is superior to other methods.