Comparison of Macintosh, McCoy, Truview EVO2, and King Vision Laryngoscopes for Intubation in Patients with Immobilized Cervical Spine: A Randomized, Controlled Trial

Abstract

Background: Immobilization of the neck in cervical spine injury patients can lead to misalignment of the oral, pharyngeal, and laryngeal axis, thereby making intubation more difficult. The principal aim of our study was to compare the efficacy of King Vision, Truview Evo2, and McCoy with Macintosh laryngoscope in patients getting intubated with cervical spine immobilized using manual inline stabilization. Materials and Methods: This was a randomized, controlled trial of 160 patients who were randomized to undergo surgery under general anesthesia with endotracheal intubation. We equally divided the subjects into using either Macintosh, McCoy, Truview Evo2, and King Vision laryngoscopes to facilitate intubation. We evaluated the intubation difficulty using the Intubation Difficulty Score (IDS) and Cormack–Lehane grading. Results: King Vision, Truview Evo2, and McCoy reduced the IDS as compared to Macintosh (P < 0.001). King Vision showed a first-attempt success rate of 100%. Cormack and Lehane’s glottic views were best with King Vision followed by Truview Evo2 and there was much less need for external manipulation as compared to McCoy and Macintosh. Time taken for intubation was least with McCoy blade (22.9 ± 7.2 s, P < 0.001). Conclusion: The use of both King Vision and Truview Evo2 significantly resulted in a decreased the IDS and improved Cormack–Lehane grading as compared to Macintosh and McCoy.