How stylet use can effect confirmation of endotracheal tube position using ultrasound

None of the techniques used for confirmation of endotracheal tube (ET) placement are proven reliable 100% of the time. The purpose of our study is to determine whether ultrasound can accurately detect the passage of ET through the trachea and esophagus and to see whether this visualization is augmented with the use of a metal stylet.

A total of 7 physicians made assessments of ET positions using an ultrasound during their passage through the trachea or esophagus. A total of 40 esophageal and 40 tracheal intubations were performed randomly in a blinded fashion on a fresh, unfrozen human cadaver. Half were performed with a metal stylet and the other half without a stylet.

During transtracheal assessment regardless of stylet use, correct identification of ET position was achieved in 275 of 280 esophageal intubations and 268 of 280 tracheal intubations. The overall sensitivity was 95.7%, and specificity was 98.2%. The presence and the absence of stylet was identified in 109 of 280 and in 155 of 280 attempts, respectively. Correct identification of stylet presence yielded a sensitivity of 38.9% and a specificity of 55.4%. Ultrasound can be used by emergency physicians to accurately detect the passage of ET through the trachea and esophagus; however, stylet use did not augment ET visualization.