Videolaryngoscopes for Double Lumen Tube Intubations in Simulated Easy and Difficult Airway

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.