Fig 1.
Pre-HT/CL position (panel A, EEL and HL 80°), post-HT/CL #1 position (panel B, EEL and HL 65°), and post-HT/CL #2 position (panel C, EEL and HL 50°). The displayed model is not a study participant. Abbreviations: EEL, ear-eye line; HL, horizontal line; HT/CL, head-tilt/chin-lift maneuver.
Table 1.
Baseline characteristics of the subjects values are presented number with percent or median with interquartile range.
Fig 2.
A repeated measured analysis of variance was used to compare PEFR values for pre-HT/CL, post-HT/CL #1, and post-HT/CL #2. Abbreviations: HT/CL, head-tilt/chin-lift maneuver; PEFR, peak exploratory flow rate; RM ANOVA, repeated measured analysis of variance; SD, standard deviation.
Fig 3.
Difference in PEFRs pre-HT/CL, post-HT/CL #1, and post-HT/CL #2 among non-responders.
Abbreviations: HT/CL, head-tilt/chin-lift maneuver; PEFR, peak exploratory flow rate.
Table 2.
Comparison of baseline characteristics between HT/CL responders and non-responders.
Values are presented number with percent or median with interquartile range.
Fig 4.
Schematic mathematical model showing the relationship between airway resistance (R) and airway flow rate () pre-HT/CL, post-HT/CL #1, and post-HT/CL #2.
Two points of intersection exist in the dashed round, one point is where the laryngeal axis intersects with the pharyngeal axis, and the other point is where the pharyngeal axis intersects with the oral cavity axis. The dotted arrow indicates deviation of the laryngeal axis according to the rise of the chest. Abbreviations: HT/CL, head-tilt/chin-lift maneuver; R, airway resistance; , airway flow rate.
Fig 5.
This graph shows the airway flow according to the HT/CL angulation.
The HT/CL angulation was calculated as 90° minus the angle between the ear-eye line and the horizontal line. Abbreviation: HT/CL, head-tilt/chin-lift maneuver.