Work of breathing and lung volume during forward leaning supported by the upper limbs.

This study compared work of breathing (WOB) and the pressure time product (PTP) to verify whether WOB and PTP decrease in the forward-leaning posture compared with erect sitting. Seven healthy adults (two females and five males) adopted three sitting postures: upright, and two forward-leaning postures of 15° and 30°. The WOB was obtained using the modified Campbell diagram, and PTP was calculated as the time integral of the area between esophageal and chest wall pressure. End-expiratory lung volume and transpulmonary pressure were significantly increased in the 15° and 30° forward-leaning postures compared with erect sitting (p â‰¦ 0.05). End-inspiratory lung volume was significantly increased in the 30° forward-leaning posture compared to erect sitting (p â‰¦ 0.05). PTP and inspiratory resistive WOB were significantly lower in the 15° and 30° forward-leaning postures compared to erect sitting (p â‰¦ 0.05). Forward leaning increases lung volume, which may dilate the airways, decrease resistant WOB, and reduce respiratory muscle activity.

Effects of postural differences on intrapleural pressure during chest wall compression in healthy males.

[Purpose] This study aimed to investigate the difference in intrapleural pressure between the supine and lateral decubitus positions during manual chest wall compression. [Participants and Methods] Eight healthy males participated in this study. The same physiotherapist performed chest wall compression on participants lying supine, and on their right and left sides. We noted changes in intrapleural pressure and lung volume in each participant during quiet breathing and chest wall compression. [Results] During chest wall compression, intrapleural pressure at the end-expiratory lung volume and the end-inspiratory lung volume were lower in the right and left decubitus positions than in the supine position. We observed the following low inflection points in the pressure-volume loops during chest wall compression: all participants in the supine position, no participants in the right decubitus position, and two participants in the left decubitus position. [Conclusion] Chest wall compression in the bilateral decubitus positions may not cause excessive intrapleural pressure on the airway and alveoli as compared to chest wall compression in the supine position.