title: Bedside ultrasound of the neck confirms endotracheal tube position in emergency intubations.
abstract: OBJECTIVE
  In controlled environments such as the operating room, bedside ultrasound (BUS) of the neck has shown high accuracy for distinguishing endotracheal (ETI) from esophageal intubations. We sought to determine the accuracy of BUS for endotracheal tube (ETT) position in the emergency department (ED) setting.
  
  
  METHODS
  We assessed the utility of BUS in a single-center observational study in an ED setting. BUS was performed either simultaneously with ED intubation (S/ED), within < 3 minutes of ED intubation (A/ED), or in < 3 minutes of patient's ED arrival after pre-hospital intubation (A/EMS). Trained ED providers performed BUS; intubators were blinded to ultrasound findings. We used Cormack and Lehane categories (CL) to classify intubation attempts as "easy" (CL-I/II), "moderate" (CL-III) and "difficult" (CL-IV). Additional data included the diagnostic accuracy of the sonographer and intubator compared to the clinical outcome, anatomy identified by sonography and time to diagnosis.
  
  
  RESULTS
  During a 10-month period, 89 subjects with 115 intubation attempts were included in the study, and 86 patients/101 attempts with complete data were used in the study (63-easy, 19-moderate, 19-difficult). The sonographers achieved 100 % accuracy with respect to determining the correct ETT position utilizing an anterior neck approach, while the intubators' accuracy in assessing correct tube location was 97 % compared to the clinical outcome. A blinded review of sonography findings confirmed all BUS anatomical findings. A sonographically empty esophagus was 100 % specific for endotracheal intubation, and a "double trachea sign" was 100 % sensitive and 91 % specific for esophageal intubation. The sonographic time to diagnosis was significantly faster than the intubator time to diagnosis ("easy" p < 0.001; n = 47; "moderate" p = 0.001; n = 15; "difficult" p < 0.001; n = 19); Wilcoxon test; A/EMS cases excluded).
  
  
  CONCLUSIONS
  In this emergency setting, ultrasound determined ETT locations rapidly with 100 % accuracy and independently of the CL-category.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston.
authors.forename: B
authors.initials: B
authors.lastname: Hoffmann
authors.affiliation: Emergency Medicine, University of Alabama at Birmingham.
authors.forename: J P
authors.initials: JP
authors.lastname: Gullett
authors.affiliation: Emergency Medicine, Johns Hopkins University, Baltimore.
authors.forename: H F
authors.initials: HF
authors.lastname: Hill
authors.affiliation: Emergency Medicine, Emergency Medicine Associates, Germantown.
authors.forename: D
authors.initials: D
authors.lastname: Fuller
authors.affiliation: Emergency Medicine, University of Wisconsin School of Medicine, Madison.
authors.forename: M C
authors.initials: MC
authors.lastname: Westergaard
authors.affiliation: Emergency Medicine, Onslow Memorial Hospital, Jacksonville.
authors.forename: W T
authors.initials: WT
authors.lastname: Hosek
authors.affiliation: Pulmonary Medicine, University Hospital of South Manchester, Manchester.
authors.forename: J A
authors.initials: JA
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004632:Emergency Medical Services; D004636:Emergency Service, Hospital; D004947:Esophagus / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging*; D019095:Point-of-Care Systems; D011446:Prospective Studies; D012151:Resuscitation; D016037:Single-Blind Method; D013996:Time and Motion Studies; D014132:Trachea / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D014947:Wounds and Injuries / Q000000981:diagnostic imaging / Q000628:therapy; D055815:Young Adult