Role of noninvasive ventilators: for early respiratory failure, to reduce tracheal intubation or tracheotomy, and to provide a transition between oxygen therapy and invasive breathing. Side effects of noninvasive breathing: dryness of the mouth and throat, mask compression, skin damage to the bridge of the nose, claustrophobia, flatulence, aspiration, sputum evacuation disorders, air leakage, intolerance, and sleep upper airway obstruction. Noninvasive ventilators can be used in the early stages of respiratory failure to reduce lesions and organ damage resulting from respiratory failure; they reduce tracheal intubation and tracheotomies, thereby avoiding complications; and they provide a transition between oxygen therapy alone and invasive ventilator-assisted ventilation. Invasive ventilation can be overused when it is difficult to use, or when an invasive ventilator is withdrawn. Noninvasive ventilators should not be used in patients with cardiac or respiratory arrest, weak spontaneous breathing, coma, aspiration, pneumothorax, or upper airway obstruction.