Prehospital use of a prototype esophageal detection device: a word of caution!

OBJECTIVE: To determine the effectiveness of a prototype esophageal detection device (EDD) during use in the prehospital setting. DESIGN/SETTING: Prospective convenience sample in a prehospital setting. POPULATION: Intubated adult patients. INTERVENTIONS: The study device was used to determine esophageal or endotracheal placement of endotracheal tubes in intubated patients. Clinical means were used to confirm tube location. A data sheet was completed for each patient. RESULTS: Of 105 uses of the device, 17 of 17 esophageal tubes were identified correctly (100% sensitivity). Sixty-five of 88 tracheal tubes were correctly identified (78% specificity). There was intermediate reinflation of the device on 13 of the 65 tracheal tubes. Five tests were indeterminate. There were no false negatives (negative predictive value 100%), but 18 false positives (positive predictive value 48%). CONCLUSION: This prototype EDD adequately identifies esophageally placed endotracheal tubes. Correct identification of endotracheally placed tubes was less sensitive. Much work needs to be done regarding the use of negative aspiration devices to identify placement of endotracheal tubes.

Evaluation of a prototype esophageal detection device.

OBJECTIVE: To determine the ability of a prototype esophageal detection device (EDD) to identify esophageal misplacement of an endotracheal (ET) tube. METHODS: A prospective, randomized, blinded study of detection of esophageal intubation was conducted using 51 elective surgical patients who met inclusion criteria. A squeeze-bulb aspirator that creates a negative pressure of -80 to -90 torr was used for detection of esophageal intubation. The bulb should reinflate rapidly if the tube is in the noncollapsible trachea, but should not reinflate if the tube is in the collapsible esophagus. Each patient was prepared for surgery in the usual manner. The anesthesiologist placed an ET tube into the trachea. An identical tube was advanced the same distance into the esophagus. The tubes were labeled "A" or "B" according to a computer-generated random number list. An evaluator, who was blinded to the placement of the tubes, assessed one tube with the EDD. For most patients, a second evaluator, who was blinded to both tube placement and the results of the first evaluator, assessed the other tube. During evaluation, the tube cuffs were deflated. After data collection, the esophageal tube was removed and surgery was completed. RESULTS: All 45 esophageal tube placements were correctly identified. Thirty-five of the 40 ET tubes were correctly identified. Of the five ET tubes mislabeled, three were found in a mainstem bronchus. All had delayed bulb re-expansion. CONCLUSION: This prototype EDD is a useful method of identifying esophageal misplacement of an ET tube in anesthetized adult surgical patients.