Ultrasonography for the Confirmation of Endotracheal Tube Intubation: A Systematic Review and Meta-Analysis

Study objective: Intubation is routinely performed in the emergency department, and rapid, accurate confirmation is essential to avoid potentially serious adverse outcomes. The number of studies assessing ultrasonography for the verification of endotracheal tube placement has expanded rapidly in recent years. We performed this systematic review and meta-analysis to determine the sensitivity and specificity of transtracheal ultrasonography for the verification of endotracheal tube location. Methods: PubMed, the Cumulative Index of Nursing and Allied Health, Scopus, Latin American and Caribbean Health Sciences Literature database, the Cochrane databases, and bibliographies of selected articles were assessed for all prospective and randomized controlled trials evaluating the accuracy of transtracheal ultrasonography for identifying endotracheal tube location. Data were dual extracted into a predefined worksheet and quality analysis was performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Data were summarized and a meta-analysis was performed with subgroup analyses by location, specialty, experience, transducer type, and technique. Time to confirmation was assessed as a secondary outcome. Results: This systematic review identified 17 studies (n=1,595 patients). Overall, transtracheal ultrasonography was 98.7% sensitive (95% confidence interval [CI] 97.8% to 99.2%) and 97.1% specific (95% CI 92.4% to 99.0%), with a positive likelihood ratio of 34.4 (95% CI 12.7 to 93.1) and a negative likelihood ratio of 0.01 (95% CI 0.01 to 0.02). Subgroup analyses did not demonstrate a significant difference by location, provider specialty, provider experience, transducer type, or technique. Mean time to confirmation was 13.0 seconds. Conclusion: Transtracheal sonography is rapid to perform, with an acceptable degree of sensitivity and specificity for the confirmation of endotracheal intubation. Ultrasonography is a valuable adjunct and should be considered when quantitative capnography is unavailable or unreliable.