Open AccessChanges in peak expiratory flow rates using two head-tilt/chin-lift maneuver angles in young healthy conscious volunteers
Author(s) -
Sion Jo,
Jae Baek Lee,
Young Ho Jin,
Tak Jeong,
Jae Chol Yoon,
Boyoung Park,
Joon Min Jung
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0224155
Subject(s) - chemistry , medicine
Background The head-tilt/chin-lift (HT/CL) maneuver is simple and routinely used to open a closed upper airway. Objectives It has yet to be determined whether increasing the HT/CL angle further would be beneficial. Methods We enrolled 60 (30 males) 20-year-old conscious participants. Pre-HT/CL, post-HT/CL #1, and post-HT/CL #2 positions were defined as positions in which the angle between the ear–eye line and the horizontal line was 80°, 65°, and 50°, respectively. Peak exploratory flow rates (PEFRs) pre-HT/CL, post-HT/CL #1, and post-HT/CL #2 positions were recorded continuously at 1-minute intervals (one set). Five sets of measurements were performed (total, 15 measurements for each participant). Results We analysed 900 measurements (180 sets). The mean PEFRs pre-HT/CL, post-HT/CL #1, and post-HT/CL #2 positions were 348.4 ± 96.9, 366.4 ± 104.9, and 378.8 ± 111.2 L/min (percentage change compared to pre-HT/CL, 5.2% and 8.7%), respectively. Significant differences were observed among pre-HT/CL, post-HT/CL #1, and post-HT/CL #2 positions in all participants, as well as in subgroup classified according to sex, and medians of height, body weight, and body mass index. Conclusion Our findings suggest that a greater HT/CL angle would be beneficial, as the PEFR increased gradually. The decreasing manner in the PEFR increase with the HT/CL angle implies the existence of an angle threshold beyond which there were no further benefits in airflow, indicating a minimum in airway resistance. A HT/CL maneuver may be appropriate until locking the atlanto-occipital and cervical spine joints in extension occurs and the chest (sternal notch) begins to rise.