The role of noninvasive ventilation in acute cardiogenic pulmonary edema

Citation Gray A, Goodacre S, Newby DE, Masson M, Sampson F, Nicholl J: Noninvasive ventilation in acute cardiogenic pulmonary edema. N Engl J Med 2008, 359:142-151 [1]. Background Noninvasive ventilation (NIV) (continuous positive airway pressure [CPAP] or noninvasive intermittent positivepressure ventilation [NIPPV]) appears to be of benefi t in the immediate treatment of patients with acute cardiogenic pulmonary edema and may reduce mortality. Methods Objective: To determine whether noninvasive ventilation reduces mortality and whether there are important diff erences in outcome associated with the method of treatment (CPAP or NIPPV). Design: Open, prospective, randomized controlled trial. Setting: 26 emergency departments in hospital in the UK between July 2003 and April 2007. Subjects: 1069 patients age >16 years with a clinical diagnosis of acute cardiogenic pulmonary edema, as determined by chest radiograph, respiratory rate >20 breaths/min, and arterial pH<7.35. Exclusion criteria included a requirement for a lifesaving or emergency intervention, inability to give consent, or previous recruitment in the trial. Intervention: All patients received standard concomitant therapy. Patients were randomly assigned to standard oxygen therapy (up to 15 liters per minute via face mask), CPAP (5 to 15 cm of water), or NIPPV (inspiratory pressure, 8 to 20 cm of water; expiratory pressure, 4 to 10 cm of water). Outcomes: The primary end point for the comparison between noninvasive ventilation and standard oxygen therapy was death within 7 days after the initiation of treatment, and the primary end point for the comparison between NIPPV and CPAP was death or intubation within 7 days. Results A total of 1069 patients (mean [±SD] age, 77.7±9.7 years; female sex, 56.9%) were assigned to standard oxygen therapy (367 patients), CPAP (346 patients), or NIPPV (356 patients). There was no signifi cant diff erence in 7-day mortality between patients receiving standard oxygen therapy (9.8%) and those undergoing noninvasive ventilation (9.5%, P=0.87). There was no signifi cant diff erence in the combined end point of death or intubation within 7 days between the two groups of patients undergoing noninvasive ventilation (11.7% for CPAP and 11.1% for NIPPV, P=0.81). As compared with standard oxygen therapy, noninvasive ventilation was associated with greater mean improvements at 1 hour after the beginning of treatment in patient-reported dyspnea (treatment diff erence, 0.7 on a visual-analogue scale ranging from 1 to 10; 95% confi dence interval [CI], 0.2 to 1.3; P=0.008), heart rate (treatment diff erence, 4 beats per minute; 95% CI, 1 to 6; P=0.004), acidosis (treatment diff erence, pH 0.03; 95% CI, 0.02 to 0.04; P<0.001), and hypercapnia (treatment diff erence, 0.7 kPa [5.2 mm Hg]; 95% CI, 0.4 to 0.9; P<0.001). There were no treatment-related adverse events. Conclusion In patients with acute cardiogenic pulmonary edema, noninvasive ventilation induces a more rapid improvement in respiratory distress and metabolic disturbance than does standard oxygen therapy but has no eff ect on short-term mortality.