Helmet CPAP vs. oxygen therapy in severe hypoxemic respiratory failure due to pneumonia

The efficacy of noninvasive continuous positive airway pressure (CPAP) to improve outcomes in severe hypoxemic acute respiratory failure (hARF) due to pneumonia has not been clearly established. The aim of this study was to compare CPAP vs. oxygen therapy to reduce the risk of meeting criteria for endotracheal intubation (ETI). In a multicenter randomized controlled trial conducted in four Italian centers patients with severe hARF due to pneumonia were randomized to receive helmet CPAP (CPAP group) or oxygen delivered with a Venturi mask (control group). The primary endpoint was the percentage of patients meeting criteria for ETI, including either one or more major criteria (respiratory arrest, respiratory pauses with unconsciousness, severe hemodynamic instability, intolerance) or at least two minor criteria (reduction of at least 30 % of basal PaO2/FiO(2) ratio, increase of 20 % of PaCO2, worsening of alertness, respiratory distress, SpO(2) less than 90 %, exhaustion). Between February 2010 and 2013, 40 patients were randomized to CPAP and 41 to Venturi mask. The proportion of patients meeting ETI criteria in the CPAP group was significantly lower compared to those in the control group (6/40 = 15 % vs. 26/41 = 63 %, respectively, p < 0.001; relative risk 0.24, 95 % CI 0.11-0.51; number needed to treat, 2) two patients were intubated in the CPAP group and one in the control group. The CPAP group showed a faster and greater improvement in oxygenation in comparison to controls (p < 0.001). In either study group, no relevant adverse events were detected. Helmet CPAP reduces the risk of meeting ETI criteria compared to oxygen therapy in patients with severe hARF due to pneumonia.