title: Sonographic confirmation of intubation: comparison of 3 methods in a pig model.
abstract: OBJECTIVE
  Several recent studies have investigated methods to confirm endotracheal tube (ETT) placement with sonography, using diaphragmatic movement, lung sliding, and transtracheal visualization of the ETT. To our knowledge, no studies have directly compared these 3 methods. This study aimed to directly compare the test characteristics of these 3 methods to determine ETT placement. Additionally, we compared the time required to complete the sonographic examination and the performers' confidence in their findings.
  
  
  METHODS
  We conducted a prospective randomized single-blinded study. Twenty-five recently euthanized pigs were intubated either in the esophagus or trachea, for a total of 50 intubations. Each of the 3 sonographic methods of intubation confirmation was performed by sonographers of different skill levels. Sonographic findings, the time to findings, and confidence in findings were recorded.
  
  
  RESULTS
  A total of 150 sonographic examinations were performed. There were no significant differences in the sensitivity, specificity, positive predictive value, negative predictive value, or accuracy for correct ETT placement between the 3 methods of intubation confirmation. On average, the transtracheal and thoracic methods were faster (12.5 and 14.0 seconds, respectively) than the diaphragmatic method (21.0 seconds; P < .01). There were no significant differences in operator confidence between the confirmation methods.
  
  
  CONCLUSIONS
  All 3 methods for determining ETT placement had similar test characteristics. Transtracheal and thoracic sonography were faster than diaphragmatic sonography for determining ETT placement in pigs.
authors.affiliation: Department of Emergency Medicine, Tufts University School of Medicine, Baystate Medical Center, Springfield, Massachusetts USA (G.B., L.L.); and Department of Emergency Medicine, University of Vermont, Burlington, Vermont USA (D.M., A.S.). gavin.budhram@gmail.com.
authors.forename: Gavin
authors.initials: G
authors.lastname: Budhram
authors.affiliation: Department of Emergency Medicine, Tufts University School of Medicine, Baystate Medical Center, Springfield, Massachusetts USA (G.B., L.L.); and Department of Emergency Medicine, University of Vermont, Burlington, Vermont USA (D.M., A.S.).
authors.forename: David
authors.initials: D
authors.lastname: Murman
authors.affiliation: Department of Emergency Medicine, Tufts University School of Medicine, Baystate Medical Center, Springfield, Massachusetts USA (G.B., L.L.); and Department of Emergency Medicine, University of Vermont, Burlington, Vermont USA (D.M., A.S.).
authors.forename: Lucienne
authors.initials: L
authors.lastname: Lutfy
authors.affiliation: Department of Emergency Medicine, Tufts University School of Medicine, Baystate Medical Center, Springfield, Massachusetts USA (G.B., L.L.); and Department of Emergency Medicine, University of Vermont, Burlington, Vermont USA (D.M., A.S.).
authors.forename: Alison
authors.initials: A
authors.lastname: Sullivan
mesh_terms: D000818:Animals; D003964:Diaphragm / Q000000981:diagnostic imaging*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007442:Intubation, Intratracheal / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013552:Swine; D014132:Trachea / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional / Q000379:methods*
keywords: confirmation; emergency ultrasound; esophageal; imaging; intubation; sonography