Background: Video analysis of body and gaze movements has recently become widespread, mainly in the field of engineering, however, few medical studies have used motion capture and eye-tracking systems. The aim of this study was to test the hypothesis that head movements and gaze distribution during tracheal intubation differ between practitioners who are expert at tracheal intubation and those who are novice at tracheal intubation as a secondary analysis of our previous study.
Methods: Practitioners who were either novices or experts at tracheal intubation using Macintosh laryngoscopes were recruited. Head movement and gaze distribution during tracheal intubation into a mannequin were recorded using motion capture and eye-tracking systems and analyzed according to 3 phases: phase A (mouth opening), B (obtaining vocal cord view), and C (tracheal intubation). The values obtained were compared between novices and experts.
Results: Intra-group comparison showed significant differences in the height of the head and forward-backward head tilt during tracheal intubation in the experts and novices, respectively. Inter-group comparison showed significant differences at each phase except for the height of the head at phase A (height: 154.1 vs. 159.1 cm, p = 0.602 for Phase A; 150.6 vs. 141.3 cm, p < 0.001 for Phase B; 151.2 vs. 135.6 cm, p < 0.001 for Phase C; tilt: 2.9 vs. 6.4 cm, p < 0.001 for Phase A; 6.5 vs. 9.3 cm, p < 0.001 for Phase B; 6.2 vs. 8.4 cm, < 0.001 for Phase C). Gaze depth analysis indicated that the experts had a further gaze distance. While the experts continued looking down throughout the tracheal intubation, the novices looked up after the mouth opening phase until the accomplishment of intubation.
Conclusion: Posture and gaze distribution during tracheal intubation with a laryngoscope differed between novices and experts. The results of this study will help trainers develop a clear teaching policy and help trainees become aware of their posture during tracheal intubation training.