Variables: Mucus clearance will be assessed through wet volume of suctioned sputum through a suction catheter connected to a sterile collector container. Pulmonary mechanics will be measured before, after and 1 h post-intervention through a pneumotachograph (PNT). Peak expiratory flow (PEF) generated by MI-E will be continuously measured through a PNT. Hemodynamic measurements will be recorded before, after and 1 h post-intervention.