title: Defining the learning curve of point-of-care ultrasound for confirming endotracheal tube placement by emergency physicians.
abstract: BACKGROUND
  Unrecognized esophageal intubations are associated with significant patient morbidity and mortality. No single confirmatory device has been shown to be 100 % accurate at ruling out esophageal intubations in the emergency department. Recent studies have demonstrated that point-of-care ultrasound (POCUS) may be a useful adjunct for confirming endotracheal tube placement; however, the amount of practice required to become proficient at this technique is unclear. The purpose of this study is to determine the amount of practice required by emergency physicians to become proficient at interpreting ultrasound video clips of esophageal and endotracheal intubations.
  
  
  METHODS
  Emergency physicians and emergency medicine residents completed a baseline interpretation test followed by a 10 min online tutorial. They then interpreted POCUS clips of esophageal and endotracheal intubations in a randomly selected order. If an incorrect response was provided, the participant completed another practice session with feedback. This process continued until they correctly interpreted ten consecutive ultrasound clips. Descriptive statistics were used to summarize the data.
  
  
  RESULTS
  Of the 87 eligible physicians, 66 (75.9 %) completed the study. The mean score on the baseline test was 42.9 % (SD 32.7 %). After the tutorial, 90.9 % (60/66) of the participants achieved proficiency after one practice attempt and 100 % achieved proficiency after two practice attempts. Six intubation ultrasound clips were misinterpreted, for a total error rate of 0.9 % (6/684). Overall, the participants had a sensitivity of 98.3 % (95 % CI 96.3-99.4 %) and specificity of 100 % (95 % CI 98.9-100 %) for detecting correct tube location. Scans were interpreted within an average of 4 s (SD 2.9 s) of the intubation.
  
  
  CONCLUSIONS
  After a brief online tutorial and only two practice attempts, emergency physicians were able to quickly and accurately interpret ultrasound intubation clips of esophageal and endotracheal intubations.
authors.affiliation: Department of Emergency Medicine, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. jordan.chenkin@utoronto.ca.|Division of Emergency Medicine, University of Toronto, 2075 Bayview Avenue C753, Toronto, ON, M4N 3M5, Canada. jordan.chenkin@utoronto.ca.
authors.forename: Jordan
authors.identifier: http://orcid.org/0000-0002-0303-6776
authors.initials: J
authors.lastname: Chenkin
authors.affiliation: Department of Anesthesiology, University of Ottawa, Room B311, 1053 Carling Avenue, Mail Stop 249, Ottawa, ON, K1Y 4E9, Canada. cjlmccartney@gmail.com.
authors.forename: Colin J L
authors.initials: CJ
authors.lastname: McCartney
authors.affiliation: Department of Emergency Medicine, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. tjelic@gmail.com.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Jelic
authors.affiliation: Division of Emergency Medicine, University of Toronto, 2075 Bayview Avenue C753, Toronto, ON, M4N 3M5, Canada. m.romano@mail.utoronto.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: Romano
authors.affiliation: Division of Emergency Medicine, University of Toronto, 2075 Bayview Avenue C753, Toronto, ON, M4N 3M5, Canada. clheslop@gmail.com.
authors.forename: Claire
authors.initials: C
authors.lastname: Heslop
authors.affiliation: Division of Emergency Medicine, University of Toronto, 2075 Bayview Avenue C753, Toronto, ON, M4N 3M5, Canada. Glen.Bandiera@utoronto.ca.|Department of Emergency Medicine, St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B 1W8, Canada. Glen.Bandiera@utoronto.ca.
authors.forename: Glen
authors.initials: G
authors.lastname: Bandiera
keywords: Education; Endotracheal intubation; Endotracheal intubation confirmation; Ultrasonography; Upper airway ultrasound