The assessment of four different methods to verify tracheal tube placementin the critical care setting

One of the most serious complications of conventional endotracheal intubati on is unidentified placement of the tube in the esophagus. The aim of our s tudy was to evaluate four different methods for immediate detection of the tube position: auscultation, capnographic determination of ETCO2, esophagea l detection method (EDM) using a self-inflating bulb, and the transillumina tion method using a lighted stylet (Trachlight(TM); Laerdal, Armonk, NY). T hirty-eight endotracheally intubated patients admitted to our medical inten sive care unit were enrolled in the study. A second identical tube was inse rted into the esophagus under laryngoscopic control. The endotracheal tube was then disconnected from the ventilator. Two blinded examiners, one exper ienced, the other inexperienced, determined the tube position within 30 s u sing one of the four methods. The order of the tubes tested and the methods used were randomized. In 130 of 152 examinations,both examiners correctly diagnosed the position of the tube. The wrong result was obtained by both e xaminers 4 times; only the experienced examiner was wrong 4 times, and only the inexperienced examiner was wrong 14 times. Using ETCO2, both examiners were correct in all cases. Auscultation showed an obvious relation to the examiner's experience: the experienced examiner was correct in all cases, t he inexperienced examiner was correct in only 68% of cases. Using the self- inflating bulb, there were two wrong results of the experienced examiner an d one wrong result of the inexperienced examiner. The transillumination tec hnique was associated with a high error rate by both examiners (16% and 13% , respectively). Comparing all four methods showed that capnography is supe rior to auscultation (P = 0.0005) and to the Trachlight(TM) detection metho d (P = 0.0078). EDM was not statistically superior to auscultation and tran sillumination. Capnography was the most reliable method for rapid evaluatio n of tube position, followed by EDM, whereas auscultation and Trachlight(TM ) did not seem to be of comparable value. Experience was a determining fact or for auscultation. Implications: To prevent unidentified esophageal intub ation, a serious complication in the critical care setting, four methods fo r detecting tube position were tested by two examiners (one experienced, th e other inexperienced) in endotracheally intubated patients after insertion of a second tube into the esophagus.