Effect of nocturnal EPAP titration to abolish tidal expiratory flow limitation in COPD patients with chronic hypercapnia: a randomized, cross-over pilot study oleh Emanuela Zannin, Ilaria Milesi, Roberto Porta, Simona Cacciatore, Luca Barbano, R. Trentin, Francesco Fanfulla, Michele Vitacca, Raffaele L. Dellacà