Three-window ultrasonography confirmation of endotracheal tube placement

Background: Establishing a definitive airway is often an initial step in the management of critically ill patients in the emergency department (ED). Currently, there is no universally accepted gold standard for airway confirmation. Recent literature has shown that point-of-care ultrasound (POCUS) may be helpful in confirming the correct endotracheal tube (ETT) placement. Objective: The objective of this study is to evaluate the accuracy of a comprehensive three-window POCUS assessment to confirm correct ETT placement. Methods: This was a prospective, single-center, observational study using a convenience sample of patients in the ED and Medical Intensive Care Unit. After presumed successful ETT intubation, three sonographic windows were obtained, which included the trachea, bilateral lung sliding, and diaphragm movement. Results: We enrolled a total of 140 patients. There were no esophageal intubations. The three-window POCUS method correctly identified 132 of 137 ETTs placed in the trachea with 96.4% sensitivity (95% confidence interval [CI] 91.7%–98.8%) and 33.3% specificity (95% CI 0.8%–90.6%). Only one of the three mainstem intubations was identified using POCUS. Ultrasound assessment was completed on average 25 min quicker than the usual confirmatory plain film radiography (95% CI 6.2–43.9 min, P = 0.005). Conclusions: The three-window POCUS assessment is a rapid and potentially reliable method to identify ETT intubation, but may not be reliable at confirming mainstem intubation.