Diagnostic accuracy of auscultation and lung ultrasound in the assessment of adequate double lumen tube position for anesthetic trainee doctors - a single center, prospective study

Lung ultrasound can be used to assess adequate regional ventilation, similar to auscultation. Therefore, we evaluated whether the diagnostic accuracy of lung ultrasound was superior to that of auscultation in the assessment of proper double lumen tube (DLT) position, which were performed by anesthetic trainees. We conducted a single-center, prospective study of 69 patients. DLT insertion, auscultation, lung ultrasound, and fiberoptic bronchoscopy were sequentially conducted in the same patients in the supine and lateral positions. During lung ultrasound, the proper DLT position was defined when the lung pulse and barcode sign were visible on the non-ventilated lung, and lung sliding and seashore sign were observed in the ventilated lung. Fiberoptic bronchoscopy was performed for final verification of the DLT position as a standard test. Contingency tables were plotted to determine accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each method. The primary outcome of this study was the accuracy of each method. Accuracy (60.9%), sensitivity (100%), specificity (12.9%), PPV (58.5%), and NPV (100%) of ultrasound were equal to those of auscultation in the supine position. Accuracy (89.9%), sensitivity (100%), specificity (36.4%), PPV (89.2%), and NPV (100%) of ultrasound were equal to that of auscultation in the lateral position. The prevalence of proper lung isolation was 55.1% in the supine position, and it increased to 84.1% in the lateral position. Lung ultrasound is not superior to auscultation for determination of the proper DLT position in both the supine and lateral positions.