Abstract：
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.
摘要：
虽然视频喉镜检查解决了声门暴露的问题，当气管导管形状不均匀时，很难将导管输送到声门开口。本研究旨在比较不同管形对视频喉镜辅助气管插管患者首过成功率（FPS）的影响。该研究包括300名18岁以上接受全身麻醉并需要气管插管的患者。参与者被随机分为三组，每组100人，如下：A组，带有自配探针的视频喉镜用于管的预整形；B组：视频喉镜刀片的曲率被建模用于管的预整形；C组：管预整形角度与视频喉镜刀片一致，弯曲点设置在气管导管袖口上方1cm处。主要结果是FPS率。次要结果包括气管插管时间，血流动力学反应和不良事件。患者特征或气道评估无显著差异(P>0.05)。与A组相比,B组和C组表现出更高的FPS率(68%vs.86%vs.92%;P<0.001)。然而,B组与C组FPS发生率差异无统计学意义(P>0.05)。C组气管插管时间明显少于A组和B组（22.21±4.01vs.19.92±4.11vs.17.71±3.47；P<0.001）。在视频喉镜辅助气管内插管期间，叶片弯曲的直袖探针预成形可以提供更高的FPS率和更短的气管插管时间。试验注册：中国临床试验注册中心，ChiCTR1900026019。
