Aspirated air capnography with esophageal detector device to confirm tracheal intubation in rapid sequence induction

Verification of the proper placement of a tracheal tube by capnography in rapid sequence induction can lead to aspiration if the patient is ventilated with the tube in the esophagus. In this study we have associated the capnography with the esophageal detector device as modified by Nunn. In 49 patients, two endotracheal tubes were introduced, one in the esophagus and the other in the trachea. An anesthesiologist, unaware of which tube is in the trachea, squeezed the bulb of the esophageal detector device, attached it to the sidestream of the capnography and the endotracheal tubes, then released it. No reinflation of the bulb was seen with the esophageal tube. Two types of reinflation were seen with the tracheal tube: slow (6 cases), all were obese, and instant (43 cases) in the remaining patients. The air aspirated from the respiratory tract by the bulb was analyzed by the capnograph; CO2 was detected from all the tracheal tubes but not from the esophageal ones. We concluded that the esophageal detector device and capnography used as described in our study is a simple reliable test to confirm the proper placement of a tracheal tube before starting ventilation in rapid sequence induction.