A comparative study of glottis visualization according to the method of lifting the epiglottis in video laryngoscopy: indirect and direct lifting methods

The direct entry of the camera under the epiglottis may provide a better view of the glottis than the indirect lifting of the epiglottis by placing the Macintosh blade tip on the vallecula when using the video laryngoscope. This study aimed to compare the efficiency of two different methods of lifting the epiglottis during the visualization of glottis using video laryngoscopy in the same patient. This prospective study enrolled 60 patients who underwent general anesthesia with tracheal intubation. In each patient, glottic views were obtained by directly (group DE) and indirectly lifting the epiglottis (group IE). These two methods were compared using the modified Cormack and Lehane grade and the percentage of glottis opening (POGO) score as assessment parameters. Modified Cormack and Lehane grade showed a significant difference between the groups DE and IE (P = 0.004). The difference in the POGO score between the groups DE and IE was also statistically significant (87.5% and 64.4%, respectively; P < 0.001). Our results, therefore, revealed that the method of directly lifting epiglottis was better at exposing glottis than the method of indirectly lifting epiglottis using a video laryngoscope.