An optimal tracheal tube preshaping strategy for endotracheal intubation using video laryngoscopy: a randomized controlled trial

Although video laryngoscopy solves the problem of glottis exposure, it is difficult to deliver the tube to the glottic opening when the tracheal tube is unevenly shaped. This study aimed to compare the effects of different tube shapes on the first-pass success (FPS) rate in patients undergoing video laryngoscopy-assisted tracheal intubation. Three hundred patients above 18 years of age who underwent general anaesthesia and required endotracheal intubation were included in the study. The participants were randomly allocated to three groups with 100 participants in each group as follows: Group A, video laryngoscopes with a self-equipped stylet are used for tube preshaping; Group B: curvature of the video laryngoscope blade is modelled for tube preshaping; Group C: tube preshaping angle is consistent with the video laryngoscope blade, and the bending point is set 1 cm above the tracheal tube cuff. The primary outcome was FPS rates. The secondary outcomes included time to tracheal intubation, haemodynamic responses and adverse events. No significant differences in patient characteristics or airway assessments were noted (P > 0.05). Compared with Groups A, Group B and Group C exhibited a higher FPS rate (68% vs. 86% vs. 92%; P < 0.001). However, there is no significant difference in FPS rate between Group B and Group C (P > 0.05). And the time to tracheal intubation in Group C was significantly less than that in Group A and Group B (22.21 +/- 4.01 vs. 19.92 +/- 4.11 vs. 17.71 +/- 3.47; P < 0.001). The straight-to-cuff stylet preshape angulation of curvature of the blade could provide a higher FPS rate and shorter time to tracheal intubation during video laryngoscopy-assisted endotracheal intubation. Trial registration: Chinese Clinical Trial Registry, ChiCTR1900026019.