title: The esophageal detector device: a rapid and accurate method for assessing tracheal versus esophageal intubation in a porcine model.
abstract: OBJECTIVE
  To assess time and accuracy of the esophageal detector device (EDD), disposable end-tidal CO2 monitor (ETCO2), and standard clinical methods for detection of endotracheal tube placement.
  
  
  METHODS
  Prospective, randomized, single-blinded, controlled laboratory investigation.
  
  
  METHODS
  Thirty airway managers (physicians, nurse anesthetists, and paramedics) used one pig (Sus scrofa) as the intubated, respiratory depressed/arrest model.
  
  
  METHODS
  Part 1: A standard 7.5-mm endotracheal tube was placed in either the esophagus or the trachea of the anesthetized swine. Anatomic location was verified by bronchoscopy. Airway managers blinded to the endotracheal tube location were assigned randomly to identify tube position by one of three methods (EDD, ETCO2, or clinical methods). Speed and accuracy of the assessment were recorded. Part 2: A second identical tube was placed, so that both the esophagus and the trachea were intubated; then, the esophageal tube was bag-ventilated for one minute. Each blinded airway manager, using only the EDD, determined placement site of both tubes.
  
  
  RESULTS
  Part 1: Mean time to determine tube placement for group A (EDD) was 13.8 seconds; group B (ETCO2), 31.5 seconds; and group C (clinical methods), 39 seconds. Comparison by analysis of variance yielded a value of P less than .001. Both groups A and B were 100% accurate, whereas 30% of the subjects from group C mistakenly assessed an esophageal tube as in the trachea. Part 2: The EDD remained 100% sensitive and specific despite prior ventilation of the esophageal tube.
  
  
  CONCLUSIONS
  In this porcine model, the EDD and ETCO2 were more accurate than clinical methods in determining endotracheal tube placement. The EDD demonstrated a significant time advantage over both ETCO2 and clinical methods. Prior ventilation of the esophageal tube does not interfere with the accuracy of the EDD.
authors.affiliation: Department of Emergency Medicine, Madigan Army Medical Center, Tacoma, Washington.
authors.forename: R G
authors.initials: RG
authors.lastname: Foutch
authors.forename: M D
authors.initials: MD
authors.lastname: Magelssen
authors.forename: J G
authors.initials: JG
authors.lastname: MacMillan
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D004947:Esophagus; D007440:Intubation / Q000295:instrumentation* / Q000379:methods; D007442:Intubation, Intratracheal / Q000295:instrumentation / Q000379:methods; D011446:Prospective Studies; D012120:Respiration Disorders / Q000378:metabolism / Q000628:therapy*; D016037:Single-Blind Method; D013552:Swine; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide