Level 1: Likely reliable evidence
For patients with acute cardiogenic pulmonary edema, noninvasive ventilation reduces mortality and the need to intubate (JAMA. 2005;294:3124-3130). This finding is based on a meta-analysis of 15 randomized trials comparing noninvasive ventilation to conventional oxygen therapy or another noninvasive ventilation modality. Nine of the trials compared continuous positive airway pressure (CPAP) vs. oxygen therapy in 468 patients.
Comparing CPAP vs. oxygen therapy, mortality rates were 11.3% vs. 21.8% (P = 0.003, NNT 10), and the need to intubate occurred in 12.6% vs. 31.9% (P <0.001, NNT 6). In six trials (N=315) that compared noninvasive pressure support ventilation vs. oxygen therapy, mortality occurred in 10.1% vs. 16.7% (P = 0.07, NNT 16), and the need to intubate occurred in 13.8% vs. 28.8% (P = 0.002, NNT 7). A combined analysis that included 783 patients found mortality rates of 10.8% vs. 20% (P <0.001, NNT 10), and the need to intubate in 13.1% vs. 30.7% (P <0.001, NNT 6). There were no significant differences in mortality or the need to intubate in a meta-analysis of six trials that compared CPAP vs. noninvasive pressure support ventilation.