Non-invasive pressure support ventilation versus conventional oxygen therapy in acute cardiogenic pulmonary oedema: a randomised trial.

BACKGROUND: Non-invasive pressure support ventilation (NIPSV) is an effective treatment for acute respiratory failure in patients with chronic obstructive pulmonary disease. We assessed the efficacy of this therapy in acute cardiogenic pulmonary oedema in a randomised comparison with conventional oxygen therapy.

METHODS: 40 patients were randomly assigned conventional oxygen therapy or NIPSV supplied by a standard ventilator through a face mask, with adjustment of tidal volume and pressure support in addition to a positive end-expiratory pressure of 5 cm water. Physiological measurements were obtained in the first 2 h and at 3 h, 4 h, and 10 h. The main endpoints were intubation rate and resolution time. Analyses were by intention to treat.

FINDINGS: Three patients were withdrawn on the basis of clinical and chest radiography results. Endotracheal intubation was required in one (5%) of 19 patients assigned NIPSV and in six (33%) of 18 assigned conventional oxygen therapy (p=0.037). Resolution time (defined as a clinical improvement with oxygen saturation of 96% or more and respiratory rate less than 30 breaths/min) was significantly shorter in the NIPSV group (median 30 [IQR 15-53] vs 105 [50-230] min, p=0.002). NIPSV led to a rapid improvement in oxygenation in the first 2 h. There were no differences in hospital length of stay or mortality.

INTERPRETATION: In this study of acute cardiogenic pulmonary oedema, NIPSV was superior to conventional oxygen therapy. Further studies should compare NIPSV with continuous positive airway pressure.