Figure 5.

Relationship between pressure support level and muscle pressure, chest wall volume distribution and synchronization. (a) Mean ± standard error of the mean (SEM) values of transdiaphragmatic pressure (Pdi; closed symbols) and rib cage muscle pressure (Prcm; open symbols) at different levels of pressure support. **P < 0.01,***P < 0.001, versus pressure support at 5 cmH₂O. °P < 0.01, versus pressure support at 10 cmH₂O. P < 0.05, versus Prcm. (b) Mean ± SEM values of percentage contribution to tidal volume of abdomen (Vab; closed symbols) and rib cage (Vrc; open symbols) at different levels of pressure support. *P < 0.05, versus Pressure support at 5 cmH₂O. (c) Mean ± SEM values of absolute values of phase shift between rib cage (RC) and abdomen (AB) at different levels of pressure support. **P < 0.01, versus pressure support at 25 cmH₂O. °°P < 0.01 versus pressure support at 15 cmH₂O.