Comparison of the Glidescope®, the Pentax AWS®, and the Truview EVO2® with the Macintosh laryngoscope in experienced anaesthetists: a manikin study

Background. The Pentax Airwayscope (R), the Glidescope (R), and the Truview EVO2 (R) constitute three novel laryngoscopes that facilitate visualization of the vocal cords without alignment of the oral, pharyngeal, and tracheal axes. We compared these devices with the Macintosh laryngoscope in a simulated easy and difficult laryngoscopy. Methods. Thirty-five experienced anaesthetists were allowed up to three attempts to intubate in each of four laryngoscopy scenarios in a Laerdal (R) SimMan (R) manikin. The time required to perform tracheal intubation, the success rate, number of intubation attempts and of optimization manoeuvres, and the severity of dental compression were recorded. Results. In the simulated easy laryngoscopy scenarios, there was no difference between the study devices and the Macintosh in success of tracheal intubation. In more difficult tracheal intubation scenarios, the Glidescope (R) and Pentax AWS (R), and to a lesser extent the Truview EVO2 (R) laryngoscope demonstrated advantages over the Macintosh laryngoscope including a better view of the glottis, greater success of tracheal intubation, and ease of device use. The Pentax AWS (R) was more successful in achieving tracheal intubation, required less time to successfully perform tracheal intubation, caused less dental trauma, and was considered by the anaesthetists to be easier to use. Conclusions. The Pentax AWS (R) laryngoscope demonstrated more advantages over the Macintosh laryngoscope than either the Truview EVO2 (R) or the Glidescope (R) laryngoscope, when used by experienced anaesthetists in difficult tracheal intubation scenarios.