Academic Emergency Medicine Volume 11, Number 5 491
Ultrasound as a Tool to Confirm Tracheal Intubation
Alix L. Rosenstein, Robert A. Jones, Sandra L. Werner, William J. Meurer,
Michelle A. Echevarria and Charles L. Emerman
MetroHealth Medical Center/Case Western Reserve University: Cleveland, OH
ABSTRACT
OBJECTIVES: Ultrasound allows noninvasive confirmation of endotracheal tube
placement during real time, avoiding critical time delays or insufflation of the
stomach. METHODS:This was a randomized, blinded, prospective experimental study.
A cadaver was intubated a total of 120 times with placement, either tracheal or
esophageal, determined by a random-number generator. The procedure was captured
using a linear probe in a low transverse position on the anterior neck. The
sequence was observed at the bedside by three participants and videotaped to be
shown to 14 additional participants. The participants were physicians, nurses,
and paramedics. Participants scored each trial as tracheal, esophageal, or
unknown. Accuracy and 95% confidence intervals (CIs) were calculated. RESULTS:
Of the 120 trials, 53 were tracheal and 67 were esophageal. Overall accuracy
rate was 88% (CI 86.6% to 89.4%). The physicians who observed real time (n = 3)
were able to correctly identify all tracheal intubations and missed only 3 of
201 esophageal intubations, an accuracy of 99% (CI 97.6% to 99.7%). Residents (n
= 2) who viewed the video had an accuracy of 84% (CI 79.0% to 88.2%).
Aeromedical crew nurses' and physicians' (n = 6) accuracy from the video was
82.8% (CI 79.8% to 85.4%). Paramedics (n = 6) watching the video had an accuracy
of 89.2% (CI 86.7% to 91.2%). There was a statistically significant difference
between the groups (p < 0.001). CONCLUSIONS: Ultrasound may be used to assist in
the real-time evaluation of placement of an endotracheal tube. Further studies
may show increased accuracy on live models with live observation of the
procedure.