Noninvasive ventilation in cardiogenic pulmonary edema: A multicenter randomized trial

Abstract

The rationale for the use of continuous positive airway pressure (CPAP) in patients with acute pulmonary edema is based on the fact that it may limit the decline in functional residual capacity, improve respiratory mechanics and oxygenation, and decrease left ventricular afterload. However, the best therapy for treatment of an episode of acute respiratory failure due to cardiogenic pulmonary edema is controversial. Studies of the use of noninvasive pressure support ventilation (NPSV) in cardiogenic pulmonary edema have been performed in the ICU whenever respiratory failure is already present and in small groups of patients. The purpose of the present study was to compare NPSV with conventional oxygen therapy in the treatment of acute cardiogenic pulmonary edema. This multicenter study was conducted in emergency departments (EDs) and included 130 patients with acute respiratory failure who were randomly assigned to receive medical therapy plus oxygen (65 patients) or NPSV (65 patients). The main outcome measure was the need for intubation. Secondary outcomes were inhospital mortality and changes in some physiologic variables. Pao2/Fio2, respiratory rate, and dyspnea were improved significantly faster with NPSV. Intubation rate, hospital mortality, and duration of hospital stay were similar in the 2 groups. In the subgroup of hypercapnic patients, NPSV provided improvement in Paco2 significantly faster and reduced the intubation rate in comparison with medical therapy (2 of 33 versus 9 of 31). Adverse events, including myocardial infarction, were evenly distributed in the 2 groups. It would appear from these findings that the early use of NPSV during acute respiratory failure accelerates the improvement of Pao2/Fio2, Paco2, dyspnea, and respiratory rate but does not affect the overall clinical outcome. However, NPSV does reduce the intubation rate in the subgroup of hypercapnic patients.