Reliability in detection of tracheal intubation using cricoid palpation method

BACKGROUND: Unrecognized esophageal intubation remains a significant cause of anesthetic morbidity. Extensive data showed that clinical signs and methods for confirming proper tracheal tube placement were not always reliable. Advancing tracheal tube into the trachea can be detected by palpating the cricoid cartilage. We evaluated the reliability of detecting tracheal intubation by cricoid palpation methods (CPM) in this study. METHODS: Three hundred and twelve patients were enrolled. After induction of general anesthesia, patients' tracheae were intubated using rigid laryngoscope. Before tracheal intubation, an assistant applied gentle pressure over the cricoid cartilage to detect tracheal or esophageal intubation. Immediately after intubation, the assistant was asked to state whether the tracheal tube was in the trachea or in the esophagus on the basis of what had been felt as the tube passed. Tracheal intubation was confirmed by capnometer and auscultation. RESULTS: In 304 tracheal intubations, the CPM correctly detected 268 cases, giving sensitivity of 88%. In 26 esophageal intubation, the CPM correctly detected 11 esophageal cases, giving specificity of 42%. Positive predictive value and negative predictive values were 95% and 23%, respectively. Increasing body mass index decreased the sensitivity for detecting tracheal intubation by the CPM. CONCLUSIONS: The CPM alone is imperfect for tracheal tube placement confirmation. Multiple methods for detecting correct tube placement should be used, since no single method has perfect reliability.