Introduction: Tracheal intubation is an essential and critical technique in emergency and operating rooms, where the lack of proper treatment (esophageal intubation) can be catastrophic. In this study, we compared an esophageal detector device (EDD) with a capnograph (EtCo2) for verifying tracheal tube placement.
Material and methods: After the approval and support of the Research Council of Mashhad University of Medical Sciences,  In this single-subject prospective study, 114 patients who were candidates for general or orthopedic surgery were enrolled. After anesthesia and tracheal intubation, tube position was first assessed by EDD (suction bulb type), followed by evaluation using an EtCo2 monitor. Data was analyzed with SPSS v16, McNemar’s, chi-square, and t-tests. Sensitivity, specificity, and positive and negative predictive values were evaluated. P<0.05 was considered as the level of significace.
Results: In total, 114 patients underwent 124 intubation attempts due to several difficult esophageal intubations. Sensitivity and positive predictive values for EtCo2 were 100% and for EDD was 98.2% and 95.6%, respectively. Therefore, capnography was a more reliable method for verifying endotracheal tube placement (P=0.016).
Conclusion: Capnography is the gold standard for recognition of tube position. EDD was less successful (sensitivity=98.2% vs 100%) for elective situations, but it provides rapid recognition and high sensitivity for verifying the tracheal tube position, particularly in cases of emergency and cardiac arrest. Because of high sensitivity and positive predictive value, EDD can be used for tube position recognition if necessary, but EtCo2 monitor is more accurate and reliable.