Background: The unexpected displacement of the endotracheal tube (ETT) as a result of neck movements can cause endobronchial intubation and accidental extubation. The ETT is subject to movement even after its proper placement has been confirmed either clinically or radiographically.
Methods: One-hundred-seven children (2-8 yr) were divided randomly into three groups. In Group I, the ETT was entered into the main bronchus and withdrawn until equal sounds in both lung were heard, and then withdrawn 2 cm. In Group II, the ETT position was determined by placing the prescribed marks on the ETT at the level of the vocal cords, and in Group III, by palpating the ETT tip at the suprasternal notch. In all groups, the distance between the ETT tip and the carina was measured using a fiberoptic bronchoscope. The relative ETT tip position along the trachea (carina; 0%, vocal cords; 100%) was assessed in each position during neck movement.
Results: The relative position of the ETT with the patient in the neutral position in Groups I, II, and III was 21.4% +/- 6.7%, 46.5% +/- 13.0%, and 43.4% +/- 11.1%, respectively. In Group I, the relative ETT position after flexion was 9.5% +/- 10.3%, and endobronchial intubation was observed in five children (14.3%). There was no extubation or endobronchial intubation in the other two groups.
Conclusions: Positioning the ETT by auscultation places the ETT more deeply than the midtrachea, which can increase the risk of endobronchial intubation during neck flexion.