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

BackgroundVideo-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/DesignThe 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.DiscussionWe 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.Trial registrationNCT01692535

Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial

“…The detailed study protocol was published as a methods paper before the start of this clinical study. 28…”

“…Success was defined as placement of the tube in the trachea within 180 s, confirmed by end-tidal carbon dioxide. 28 Overall success rate (i.e. success in the first or second attempt) was a secondary outcome parameter.…”

Evaluation of three unchannelled videolaryngoscopes and the Macintosh laryngoscope in patients with a simulated difficult airway: a randomised, controlled trial

“…Advance MAC and KingVision and the standard Macintosh to facilitate orotracheal intubation in patients with a simulated difficult airway. Our hypothesis was that for every single device, the lower limit of the 95% confidence interval (CI) of the first‐attempt success rate for orotracheal intubation is at least 90% .…”

“…A channel was added to some videolaryngoscopes to facilitate tube guidance into the trachea, but channelled devices are often bulky and can be difficult to use in patients with limited mouth opening. We recently performed a randomised, controlled trial in patients with a simulated difficult airway that compared the performance of three videolaryngoscopes with and three videolaryngoscopes without an integrated channel . This study could not demonstrate an advantage of the channel in the hands of experienced anaesthetists.…”

A Prospective Cohort Study Comparing Medical Student Intubation on Cadaveric and Manikin Models Using the King Vision™ Videolaryngoscope and Direct Laryngoscopy

“…We believe with a more concrete selection process, we will likely be able to confirm that, for most beginners, intubation using the King Vision™ VL method will consistently demonstrate improved C-L views, success rates, and time to intubation. The King Vision™ VL is a relatively new device and as of the writing of this article, a PubMed review did not identify any hospital based clinical trials completed, although a large Swiss multicenter trial protocol is written and currently ongoing with an objective of comparing 6 VL, 3 channeled blades (King Vision™, Airtraq™, A. P. Advance™)and 3 unchanneled blades (C-MAC™, GlideScope™, McGrath™) in surgical intubation and an expected completion date of August 2015 [22].…”