a comparison of truview evo2 laryngoscope with macintosh laryngoscope in routine airway management: a randomized crossover clinical trial

Background: The Truview EVO2 blade facilitates the view of vocal cords by indirect laryngoscopy and does not require the proper alignment of the oral, pharyngeal and tracheal axes as with the Macintosh blade. Methods: In a crossover fashion, we prospectively compared the view obtained at laryngoscopy with Truview EVO2 and the Macintosh blade in 110 adult patients of either sex between the age of 18 and 60 years, who were scheduled to undergo general anesthesia with endotracheal intubation. The patients were intubated with the second laryngoscope. The preoperative airway variables, laryngoscopic view, difficulty of intubation scale (IDS) score, duration of intubation, and degree of difficulty percentage of glottic opening (POGO score) of use with each laryngoscope were compared. Results: The IDS score was low and comparable between the two laryngoscopes. The laryngeal view was easy; Modified Cormack Lehane (MCL) grade 2a or less in 98.14% of the cases with the Truview laryngoscope compared to 78.7% of the cases with the Macintosh laryngoscope. Nineteen patients of MCL grade 3, one patient of grade 2b, and seven patients of grade 2a view with the Macintosh laryngoscope had MCL grade 1 view with the Truview laryngoscope. The duration of intubation was comparable between Truview and Macintosh laryngoscopes (12.1±3.8 s vs. 10.9±2.1 s). Conclusion: Truview laryngoscope performed comparably to Macintosh laryngoscope in patients with normal airway; however, the Truview laryngoscope may be a better option in difficult airway situations when the Macintosh blade fails to show the glottic opening.