Influence of Respiratory Mechanics on Diaphragmatic Dysfunction in COPD Patients Who Have Failed NIV (RHYDIAN)

The study protocol consisted of two consecutive phases; in the first step measurements of static respiratory mechanics and end expiratory lung volume (EELV) were performed after 30 minutes of MV in volume control mode. In the second step transdiaphragmatic pressure (Pdi) was calculated by means of a sniff maneuver (Maximal Pdi) after 30 minutes of spontaneous breathing trial. Linear regression analysis and Pearson's correlation coefficient was used to asses the association between Maximal Pdi values and static and dynamic mechanical features and the association between Maximal Pdi and Pdi/Maximal Pdi.