Endotracheal Tube Placement Confirmation by Ultrasonography: A Systematic Review and Meta-Analysis of more than 2500 Patients

The integration of point-of-care ultrasound in endotracheal tube placement confirmation has been focus of many recent studies. We sought to determine the diagnostic accuracy of ultrasonography in confirmation of endotracheal intubation compared with standard confirmatory methods. We completed an extensive search of PubMed, EMBASE, Cochrane Central, Web of Science, and bibliographies of the selected articles from inception to October 2019. The search was limited to prospective studies conducted in human adults that compared the accuracy of ultrasonography in confirming the endotracheal tube position with a reference standard. The methodologic quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random-effects model summarized diagnostic accuracy statistics. Subgroup analyses by ultrasonographic signs, study location, the operator's specialty, types of transducer, the technique of ultrasound confirmation, and clinical setting (cardiac arrest vs. non–cardiac arrest) were performed. Thirty studies involving 2534 patients were selected for this meta-analysis. The estimated pooled sensitivity and specificity for ultrasonography were 0.982 (95% confidence interval [CI] 0.971–0.988) and 0.957 (95% CI 0.901–0.982), respectively. Subgroup analyses did not reveal significant difference by ultrasonographic sign used, location, the sonographer's specialty, transducer type, or ultrasound technique used. Ultrasound was also found to be a useful adjunct in confirming endotracheal tube position in the subgroup of patients with cardiac arrest, with sensitivity of 0.99 (95% CI 0.98–1.00) and specificity of 0.84 (95% CI 0.67–1.00), respectively. Ultrasonography is a valuable and reliable adjunct for endotracheal tube confirmation, including during cardiac arrest resuscitation.