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 effectiv e treatment for acute respiratory failure in patients with chronic obstruct ive pulmonary disease. We assessed the efficacy of this therapy in acute ca rdiogenic pulmonary oedema in a randomised comparison with conventional oxy gen therapy. Methods 40 patients were randomly assigned conventional oxygen therapy or N IPSV supplied by a standard ventilator through a face mask, with adjustment of tidal volume and pressure support in addition to a positive end-expirat ory 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 ra te and resolution time. Analyses were by intention to treat. Findings Three patients were withdrawn on the basis of clinical and chest r adiography results.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 wi th oxygen saturation of 96% or more and respiratory rate less than 30 breat hs/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 oxyge nation in the first 2 h. There were no differences in hospital length of st ay or mortality. Interpretation In this study of acute cardiogenic pulmonary oedema, NIPSV w as superior to conventional oxygen therapy. Further studies should compare NIPSV with continuous positive airway pressure.