The diaphragm has an expiratory braking effect in spontaneously breathing lung injured animals as shown by electrical diaphragmatic activity

Albeit defined as an inspiratory muscle, the diaphragm interacts with the respiratory system also during expiration. The expiratory load on the diaphragm derives from lung volume and hence, possibly from lung collapse. We hypothesized that the diaphragm has a braking effect during the whole expiration, preserving lung patency during SB in collapse prone lungs. We investigated this hypothesis by measuring the expiratory electrical diaphragmatic activity (EAdiexp) in the modulation of expiratory flow (Vu0027exp) in a porcine model.