A randomized study of out-of-hospital continuous positive airway pressure for acute cardiogenic pulmonary oedema: physiological and clinical effects.

AIMS In acute cardiogenic pulmonary oedema (ACPE), continuous positive airway pressure (CPAP) added to medical treatment improves outcome. The present study was designed to assess the benefit of CPAP as a first line treatment of ACPE in the out-of-hospital environment. METHODS AND RESULTS The protocol lasted 45 min, divided into three periods of 15 min. Patients with ACPE were randomly assigned in two groups: 1/Early CPAP (n = 63): CPAP alone (T0-T15); CPAP + medical treatment (T15-T30); medical treatment alone (T30-T45) and 2/Late CPAP (n = 61): medical treatment alone (T0-T15); medical treatment + CPAP (T15-T30); medical treatment alone (T30-T45). Primary endpoint: effect of early CPAP on a dyspnoea clinical score and on arterial blood gases. Secondary endpoints: incidence of tracheal intubation, inotropic support, and in-hospital mortality. T0-T15: CPAP alone had a greater effect than medical treatment on the clinical score (P = 0.0003) and on PaO(2) (P = 0.0003). T15-T30: adding CPAP to medical treatment (late CPAP group) improved clinical score and blood gases and the two groups were no longer different at T30. T30-T45: in both groups, CPAP withdrawal worsened clinical score. Six patients in 'early CPAP' group vs. 16 in 'late CPAP' group were intubated [P = 0.01, odds-ratio: OR = 0.30 (0.09-0.89)]. Dobutamine was used only in the 'late CPAP' group (n = 5), (P = 0.02). Hospital death was higher in 'late CPAP' group (n = 8) than in 'early CPAP' group (n = 2) [P = 0.05, OR = 0.22 (0.04-1.0)]. CONCLUSION When compared to usual medical care, immediate application of CPAP alone in out-of-hospital treatment of ACPO is significantly better improving physiological variables and symptoms and significantly reduces tracheal intubation incidence and in-hospital mortality.