Results: During a 10-month period, 89 subjects with 115 intubation attempts were included in the study, and 86 patients/101 attempts with complete data were used in the study (63-easy, 19-moderate, 19-difficult). The sonographers achieved 100 % accuracy with respect to determining the correct ETT position utilizing an anterior neck approach, while the intubators' accuracy in assessing correct tube location was 97 % compared to the clinical outcome. A blinded review of sonography findings confirmed all BUS anatomical findings. A sonographically empty esophagus was 100 % specific for endotracheal intubation, and a "double trachea sign" was 100 % sensitive and 91 % specific for esophageal intubation. The sonographic time to diagnosis was significantly faster than the intubator time to diagnosis ("easy" p < 0.001; n = 47; "moderate" p = 0.001; n = 15; "difficult" p < 0.001; n = 19); Wilcoxon test; A/EMS cases excluded).
