Abstract: Objective To evaluate the effects of the application of three different video laryngoscopes on simulating tracheal intubation in a difficult airway model, and to provide technical data for clinical reference when dealing with difficult airways. Methods Thirty-two intern students who had practiced in the Department of Anesthesiology for 1-3 months were selected and performed tracheal intubation using Macintosh (group M), GlideScope (group G), Hc (group H), and Airtraq (group A) laryngoscopes on an adjusted AirSim simulated difficult airway model. Total time of tracheal intubation, time to obtain the best visual field, time of tracheal tube placement, number of tracheal tube placement, and the classification of laryngeal exposure were recorded, and the VAS score was used to evaluate the strength of each laryngoscopy for optimal exposure. Results The group M had the shortest total time of tracheal intubation, time to get the best field of view, and the time of tracheal tube placement. Regarding C/L grade Ⅲ or higher glottis view, the exposure rates of the group M, the group G, the group H, and the group A were 46.9%, 6.2%, 9.3%, and 12.4%, respectively. The group H had the least number of repeated catheterizations. At optimal exposure, the group A used the least force for laryngoscopy. Conclusion For volunteers who have not used video laryngoscopes, compared with Macintosh laryngoscope when simulating tracheal intubation in a difficult airway, the selected three video laryngoscopes obviously improve the classification of laryngeal exposure, but prolong intubation time, which is unfavorable for first aid.

Key words: GlideScope video laryngoscope, Hc video laryngoscope, Airtraq video laryngoscope, Simulated difficult airway model