Helmet CPAP vs Venturi O2 to Treat Early ALI/ARDS

Mechanical ventilation through an endotracheal tube is a lifesaving procedure for acute respiratory failure. However endotracheal intubation increases patient's discomfort and stress, and represents one of the most important predisposing factors for developing nosocomial bacterial pneumonia. In conscious and cooperative patients non invasive positive pressure ventilation (NPPV) is a safe and effective mean for treating patients with acute respiratory failure (ARF), improving gas exchanges and reducing the rate of complication related to mechanical ventilation. Facial mask, that is the conventional interface for NIV, may induce intolerance because of pain, discomfort or claustrophobia leading to discontinuation of noninvasive ventilation and endotracheal intubation. Thus the improvement of the interface between patient and ventilator seems crucial to achieve a good tolerance allowing the prolonged application of noninvasive ventilation. Attempting to improve tolerability of patients we used a new interface consisting in Helmet made in latex-free PVC. No prospective randomized controlled study has been published on the comparison between Continuous Positive Airways pressure (CPAP), delivered by an helmet and the medical treatment with Oxygen supplementation to treat early acute respiratory failure and acute lung injury. Aim of the present protocol is to compare the efficacy of CPAP delivered with helmet and conventional medical treatment with oxygen supplementation via Venturi mask, to prevent ETI in patients with early hypoxemic ARF ( paO2 /FiO2 below 300).