4. Discussion
palate, glottis
In this single-center randomized controlled comparative study, the McGRATH video laryngoscope showed similar efficacy in terms of the first attempt success rate within 30 s and intubation time as compared with the conventional Macintosh laryngoscope for orotracheal intubation in patients with in-line manual stabilization using a neck collar. Meanwhile, the McGRATH group showed better glottis visualization and lower IDS scores than that of the Macintosh group in this study.Previous studies of simulated difficult airway conditions have shown inconsistent results regarding the success rate and intubation time between the McGRATH video laryngoscope and the Macintosh laryngoscope [The McGRATH video laryngoscope is associated with technical issues, such as non-intuitive hand–eye coordination through an indirect liquid crystal display (LCD) view, unlike the Macintosh direct laryngoscope, despite a better glottic view [The McGRATH video laryngoscope provided a better view of the glottis than the conventional laryngoscope in this study, which is consistent with previous reports [The McGRATH video laryngoscope requires a lesser lifting force in the same glottis grade as compared to conventional laryngoscopes during this study. Five patients in the Macintosh group required more lifting force during intubation as compared to the other patients, whereas none of the patients in the McGrath group required additional lifting force. The lifting force could increase the risk of a laryngoscopy-associated injury to the soft palate or oropharynx. The peak lifting force on the base of tongue induces stress responses which may be harmful to susceptible patients. Increased lifting force was reported in GlideScopeThis study has several limitations. First, one anaesthetist conducted all procedures to eliminate technical differences. Because of this, the investigator could not be blinded, leading to a potential bias. In addition, all endotracheal intubations were conducted alone by one skilled anesthetist in this study. In this regard, the investigator’s familiarity with the McGRATH video laryngoscope cannot represent all anesthetist. Second, we hypothesized that the first attempt success rate was 59% in the Macintosh group based on a previous study [