Objective: To compare the physiological effects and the clinical efficacy of continuous positive airway pressure (CPAP) vs standard medical treatment in elderly patients (> or =75 years) with acute hypoxemic respiratory failure related to cardiogenic pulmonary edema.
Design: A prospective, randomized, concealed, and unblinded study of 89 consecutive patients who were admitted to the emergency departments of one general, and three teaching, hospitals.
Intervention: Patients were randomly assigned to receive standard medical treatment alone ( n=46) or standard medical treatment plus CPAP ( n=43).
Measurements: Improvement in PaO(2)/FIO(2) ratio, complications, length of hospital stay, early 48-h and overall mortality, compared between the CPAP and standard treatment groups.
Results: Study groups were comparable with regard to baseline physiological and clinical characteristics (age, sex ratio, autonomy, medical history, cause of pulmonary edema). Within 1 h, noninvasive continuous positive airway pressure led to decreased respiratory rate (respiratory rate, 27+/-7 vs 35+/-6 breaths/min; p=0.009), and improved oxygenation (PaO(2)/F(I)O(2), 306+/-104 vs 157+/-71; p=0.004) compared with baseline, whereas no differences were observed within the standard treatment group. Severe complications occurred in 17 patients in the standard treatment group, vs 4 patients in the noninvasive continuous positive airway pressure group ( p=0.002). Early 48-h mortality was 7% in the noninvasive continuous positive airway pressure group, compared with 24% in the standard treatment group ( p=0.017); however, no sustained benefits were observed during the overall hospital stay.
Conclusion: Noninvasive continuous positive airway pressure promotes early clinical improvement in elderly patients attending emergency departments for a severe pulmonary edema, but only reduces early 48-h mortality.