Videolaryngoscopes for Double Lumen Tube Intubations in Simulated Easy and Difficult Airway
Condition: Staff Anaesthesiologists; Limited Experience in Using Videolaryngoscopes
Study type: Interventional

Summary: 
      The investigators hypothesized that the use of the King Vision™ and the Airtraq® VL would
      reduce the time to DLT intubation compared with the GlideScope® and Macintosh in simulated
      easy and difficult airways. The investigators have considered to assess the efficacy of each
      device in manikins before considering to evaluate them in patients undergoing thoracic
      procedures.

      Twenty-one staff anaesthesiologists who had limited prior experience in using the VLs for DLT
      intubation participated in this randomised crossover study. Following a brief demonstration
      and two practice attempts, participants were volunteered to insert a DLT using the Macintosh,
      GlideScope®, Airtraq®, and King Vision™ on two high-fidelity easy and difficult airway
      simulators in a computer-generated randomized sequence. The primary endpoint, time to DLT
      intubation, as well as, the views obtained at laryngoscopy, ease of intubation, numbers of
      laryngoscopy attempts and optimisation manoeuvers, and failure to intubation; defined as an
      attempt took longer than 150 seconds, were recorded.
    

Detailed description: 
      Several regional surveys demonstrated that most thoracic anesthesiologists are using the
      double-lumen endobronchial tubes (DLT) as the first-choice lung separation technique. DLT,
      when compared with single lumen tracheal tube, can be more difficult to insert in patients
      with difficult airways. The videolaryngoscopes (VL) have the potential to facilitate the
      placement of the DLTs for lung separation in patients with predicted or unanticipated
      difficult airway.

      The use of GlideScope® (Verathon Inc., Bothell, WA, USA), a VL with an angulated blade, has
      been associated with variable times to DLT intubation according to the prior experience of
      the operators, despite superior visualization of the glottis The channeled Airtraq® (Prodol
      Meditec S.A., Vizcaya, Spain) and standard non-channeled blade of the King Vision™ (Ambu,
      Ballerup, Copenhagen, Denmark), may offer additional benefits for DLT intubation in patients
      with limited mouth opening or restricted neck movement, in whom the use of traditional VL
      like as the Glidescope® could be difficult. This is because of the larger outer diameter, the
      distal curvature and the increased rigidity of the DLT. Of note, the longer times to DLT
      intubation with the use of different VL could be shortened with building up the operator's
      experience.

      To the best of the investigators knowledge, the comparison of the effects of the Macintosh,
      GlideScope®, Airtraq®, and King Vision™ VL on the time to DLT intubation in simulated easy
      and difficult airways has not yet been studied.

      Two high-fidelity simulators (Airway Management Trainer, model AA-3100, Laerdal, Kent, UK)
      were prepared to simulate easy and difficult airway situations, as described by Marshall et
      al. and Wang et al. The "easy" airway was established with the manikin in a neutral position.
      The "difficult" airway setting was obtained by placing an Oasis Elite™ Prone Head Rest, Adult
      (140 mm in height) (Covidien, Mansfield, MA) under the occiput and securing the head position
      with adhesive tape, object to replicate cervical-collar use. Positioning was confirmed after
      each attempt to ensure consistency.
    

Intervention name(s): Macintosh; GlideScope; Airtraq; King Vision
Intervention type(s): Device; Device; Device; Device
Intervention description(s): The participants intubated the easy airway simulator with a double lumen tube using the Macintosh laryngoscope followed with intubating the difficult airway simulator; The participants intubated the easy airway simulator with a double lumen tube using the GlideScope followed with intubating the difficult airway simulator; The participants intubated the easy airway simulator with a double lumen tube using the Airtraq followed with intubating the difficult airway simulator; The participants intubated the easy airway simulator with a double lumen tube using the King Vision followed with intubating the difficult airway simulator
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Keywords: Laryngoscope; Macintosh; Glidescope; King Vision; Airtraq; Double Lumen Tube