title: SWIVIT--Swiss video-intubation trial evaluating video-laryngoscopes in a simulated difficult airway scenario: study protocol for a multicenter prospective randomized controlled trial in Switzerland.
abstract: BACKGROUND
  Video-laryngoscopes are marketed for intubation in difficult airway management. They provide a better view of the larynx and may facilitate tracheal intubation, but there is no adequately powered study comparing different types of video-laryngoscopes in a difficult airway scenario or in a simulated difficult airway situation.
  
  
  METHODS
  The objective of this trial is to evaluate and to compare the clinical performance of three video-laryngoscopes with a guiding channel for intubation (Airtraq™, A. P. Advance™, King Vision™) and three video-laryngoscopes without an integrated tracheal tube guidance (C-MAC™, GlideScope™, McGrath™) in a simulated difficult airway situation in surgical patients. The working hypothesis is that each video-laryngoscope provides at least a 90% first intubation success rate (lower limit of the 95% confidence interval >0.9). It is a prospective, patient-blinded, multicenter, randomized controlled trial in 720 patients who are scheduled for elective surgery under general anesthesia, requiring tracheal intubation at one of the three participating hospitals. A difficult airway will be created using an extrication collar and taping the patients' head on the operating table to substantially reduce mouth opening and to minimize neck movement. Tracheal intubation will be performed with the help of one of the six devices according to randomization. Insertion success, time necessary for intubation, Cormack-Lehane grade and percentage of glottic opening (POGO) score at laryngoscopy, optimization maneuvers required to aid tracheal intubation, adverse events and technical problems will be recorded. Primary outcome is intubation success at first attempt.
  
  
  CONCLUSIONS
  We will simulate the difficult airway and evaluate different video-laryngoscopes in this highly realistic and clinically challenging scenario, independently from manufacturers of the devices. Because of the sufficiently powered multicenter design this study will deliver important and cutting-edge results that will help clinicians decide which device to use for intubation of the expected and unexpected difficult airway.
  
  
  BACKGROUND
  NCT01692535.
authors.affiliation: University Department of Anesthesiology and Pain Therapy, University Hospital of Bern, Inselspital, 3010, Bern, Switzerland. lorenz.theiler@insel.ch
authors.forename: Lorenz
authors.initials: L
authors.lastname: Theiler
authors.forename: Kristina
authors.initials: K
authors.lastname: Hermann
authors.forename: Patrick
authors.initials: P
authors.lastname: Schoettker
authors.forename: Georges
authors.initials: G
authors.lastname: Savoldelli
authors.forename: Natalie
authors.initials: N
authors.lastname: Urwyler
authors.forename: Maren
authors.initials: M
authors.lastname: Kleine-Brueggeney
authors.forename: Kristopher L
authors.initials: KL
authors.lastname: Arheart
authors.forename: Robert
authors.initials: R
authors.lastname: Greif
mesh_terms: D002983:Clinical Competence; D002985:Clinical Protocols; D004867:Equipment Design; D006785:Hospitals, University; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation*; D020704:Laryngoscopes; D007828:Laryngoscopy / Q000009:adverse effects / Q000295:instrumentation*; D059032:Learning Curve; D011446:Prospective Studies; D012107:Research Design; D016037:Single-Blind Method; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome; D014741:Video Recording / Q000295:instrumentation*
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