Functional respiratory effects of noninvasive ventilation in acute hypercapnic patients with chronic obstructive pulmonary disease

Noninvasive ventilation (NIV) is useful for improving oxygenation, decreasing hypercapnia, and avoiding invasive S4 mechanical ventilation in patients with chronic obstructive pulmonary disease (COPD) exacerbations and acute respiratory failure [1,2]. During the hospitalization, the treatment intensity is quite variable on the basis of the patient's clinical condition. Often, after the acute phase, patients need only periods of NIV followed by oxygenotherapy. NIV reduces the work of breathing and probably improves the respiratory muscular strength even when the ventilation is ended [3]. The aim of this study is to evaluate this effect in COPD submitted to NIV.