title: The use of ultrasound to guide time-critical cannula tracheotomy when anterior neck airway anatomy is unidentifiable.
abstract: OBJECTIVE
  Transtracheal or transcricothyroid placement of a cannula is a practice used in a number of aspects of airway management in anaesthesia and intensive care. In this study, we aimed to investigate whether the use of ultrasound will facilitate cannula placement in a time-critical situation in patients with difficult anterior neck airway anatomy.
  
  
  METHODS
  Fifty anaesthetists were randomised to either ultrasound-guided or conventional unguided attempts, at cannula insertion into a model simulating a patient with unidentifiable anterior neck anatomy. Endpoints were the success, and time to success, of cannula placement.
  
  
  RESULTS
  There was a significant increase in success rate (83 vs. 43%, P = 0.011) and a significant decrease in time to successful placement (median time to successful cannulation 57 vs. 110 s, P = 0.008) using ultrasound guided compared to unguided cannula placement.
  
  
  CONCLUSIONS
  If a 'can't intubate, can't oxygenate' scenario occurs in a patient with unidentifiable anterior neck airway anatomy in a location where an ultrasound machine is immediately available, we recommend that consideration is given to the use of ultrasound-guided cannula tracheotomy as the first-line rescue technique.
authors.affiliation: Southampton General Hospital, Southampton, Hampshire, UK.
authors.forename: James
authors.initials: J
authors.lastname: Dinsmore
authors.forename: Andrew M B
authors.initials: AM
authors.lastname: Heard
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Green
mesh_terms: D000776:Anesthesiology / Q000295:instrumentation / Q000379:methods*; D002404:Catheterization / Q000295:instrumentation; D057785:Catheters; D015505:Chest Tubes; D016009:Chi-Square Distribution; D004739:England; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation; D008348:Manikins; D009333:Neck; D012121:Respiration, Artificial; D013997:Time Factors; D014132:Trachea / Q000000981:diagnostic imaging*; D014140:Tracheotomy / Q000295:instrumentation; D018084:Ultrasonography, Interventional