AAEs are similar to COPD exacerbations in many ways, such as an increase in both inspiratory and expiratory indexes of airway obstruction, dynamic hyperinflation, and generation of negative pleural pressure that is necessary to overcome the intrinsic positive end-expiratory pressure (iPEEP) and increased airway resistance [21].
These include breathing parameters, tolerability of particular mask/interface type, underlying diagnosis as indication for NIV, synchronization of inspiration with drug flow, severity of airway obstruction, iPEEP presence, patient-NIV synchrony, [51] and excessive leakage probably as the most important factors.