Fig. 1From: High-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (HAPPEN): study protocol for a multicenter randomized controlled trialCONSORT diagram. AECOPD acute exacerbation of chronic obstructive pulmonary disease, NPPV noninvasive positive pressure ventilation, VT tidal volume, IPAP inspiratory positive airway pressureBack to article page