Inclusion criteria:
inclusion criteria: Patients older than 18 years and less than 60 years old, positive end expiratory pressure 7.5 cm H2O, endotracheal Intubation, attached to ventilator in volumetric mod for 48 hours, stable hemodynamic status, no chest tube, no chest trauma or: pneumothorax, Embolism, subcutaneous emphysema, burns, skin grafts and chest repair surgery, pregnancy, obesity, No use of cardiac pacemaker
Exclusion criteria:
Exclusion criteria: receiving mucolytic and diluent drugs (bromoxyn, n-acetylcysteine), cramping drugs, starting, discontinuing or changing bronchodilator expansion agents, changes in mechanical ventilation settings, bronchospasm, Increased intracranial pressure