- Background: Noninvasive ventilatory support (NIVS) is intended to provide ventilatory assistance for a wide range of respiratory disturbances. The use of NIVS for treatment of respiratory distress may be applicable in the emergency department (ED). It may prevent endotracheal intubation and, likewise, may favorably influence the course of the patient’s hospitalization, depending on the primary disease or ventilatory disturbance. Objective: To evaluate the efficacy of bilevel positive airway pressure (BiPAP) ventilation in patients with acute respiratory distress presenting in the ED. Methods: A prospective, uncontrolled, nonrandomized, nonblind study enrolled 30 patients. They were cooperative and hemodynamically stable, aged over 18 years, and presented with acute respiratory distress as defined by predetermined criteria. They were connected to a BiPAP machine through a face mask, using an initial pressure of 8/3cm H2O, which was gradually raised to 12/7cm H2O inspiratory positive airway pressure/expiratory positive airway pressure. Standard drugs, inhalation and oxygen therapies were administered as needed. The BiPAP was disconnected either upon relief of respiratory distress or on deterioration of the patient’s condition. Results: Of the 30 patients in the study, 19 had cardiogenic pulmonary edema, four had acute asthma, three had exacerbation of COPD, three had pneumonia and one had malignant pleural effusion. BiPAP was instituted subsequent to failure of standard therapies. Twenty-six patients were classified as responders to the BiPAP ventilation and four as nonresponders (three patients were intubated after 1 hour and one patient 24 hours, post BiPAP). The total length of stay (LOS) in the ED was 3–5 hours and the mean LOS in hospital was 4.1 ± 1.5 days, versus 6.5 ± 1.2 days in LOS reports of similar patients in the same hospital during 1999, who did not undergo BiPAP ventilation. No other complications were observed. Conclusions: We found BiPAP ventilation simple, safe, effective and well tolerated by patients in respiratory distress. The rate of endotracheal intubation after successful BiPAP ventilation was low. In carefully selected patients with respiratory distress, BiPAP ventilation may successfully replace endotracheal intubation.