A Research Of Teaching Effects Of Visual Laryngoscopes For Endotracheal Intubation

Purpose: To evaluate and compare the teaching effects of direct laryngoscope and different kinds of visual laryngoscopes in the application of endotracheal intubation.Methods: 1.Forty non-experienced medical students were randomly selected for the study. After the basic lesson of intubation technique, subjects were randomly divided into groups. Macintosh direct laryngoscope, Trueview EVO2 optical laryngoscope, Mc Grath Series 3 video laryngoscope, Airtraq optical laryngoscope and Glidescope Ranger video laryngoscope were used to intubate on a supine normal airway manikin for 5 times each, with a random application sequence. Learning curves were drawn and analyzed according to the average intubation time. 2.Five laryngoscopes were used to intubate on a normal airway manikin of supine position, left lateral position supine position with neck immobilized for 3 times. Total intubation time, time of glottis exposure, time of tube insertion, times of intubation attempts, times of head position adjusted, tooth damage, Cormack / Lehane classification, visual scoring of each tool, and the favorite laryngoscope were analyzed using one-way ANOVA, SNK test, K-W test and M-W test for thorough evaluation of the laryngoscopes. 3. Twenty subjects from the former experiment were selected as the experimental group, while 20 experienced anesthesiologist were selected as control group. Endotracheal intubation were performed by Mc Grath Series 3 video laryngoscope on supine normal airway patients, and data were compared between the two groups using paired t test and Fisher exact test, to evaluate the efficacy of the scope.Results: 1.The learning curve demonstrated that the total intubation time decreased by the time of intubation practiced. The Mc Grath Series 3 and Glidescope Ranger video laryngoscope has the shortest intubation time and the most flat learning curve. The Trueview EVO2 optical laryngoscope was the longest in time, with the fastest decline trend and the steepest curve comparing with the other 4 tools. 2. Mc Grath Series 3 and the Glidescope Ranger video laryngoscope were better than the other 3 tools in most cases; the Airtraq optical laryngoscope were not as good as the two, but better than the Macintosh direct laryngoscope; the Trueview EVO2 optical laryngoscope had a worse efficacy than the other four scopes. The Mc Grath Series 3 laryngoscope has the lowest Visual score, and it's the most favorable laryngoscope selected by the participants. 3. The experimental group had successfully completed the intubation using Mc Grath Series 3 video laryngoscope, but with an obvious difference with the control group.Conclusions: The intubation proficiency was positively correlated with the intubation times. The Mc Grath Series 3 video laryngoscope and the Glidescope Ranger video laryngoscope was easy to learn for non-experienced beginners. Considering the data of all 3 positions, most parameters of Mc Grath Series 3 and Glidescope Ranger video laryngoscope were better than the other laryngoscopes, with a better teaching effect. The Trueview EVO2 optical laryngoscope was hard to learn comparing with the other laryngoscopes. The final clinical experiment demonstrated that practicing intubation on an intubation manikin using Mc Grath Series 3 video laryngoscope can obtain a satisfactory clinical outcome for non-experienced beginners, with a good standard of intubation practice.