Application of noninvasive ventilation in acute respiratory failure after cardiovascular surgery.

Objective: To examine ventilatory response, oxygenation-related, and hemodynamics of patients with hypoxemic acute respiratory failure (ARF) submitted to noninvasive mechanical ventilation (NIV) during the postoperative phase of cardiovascular surgery in order to identify predictive variables of success, and to compare the different types of NIV.

Methods: Seventy patients with hypoxemic ARF were randomized to one of three modalities of NIV--continuous positive airway pressure (CPAP) and ventilation with two pressure levels (PEEP + SP and BiPAP). Ventilation, oxygenation-related, and hemodynamics variables were analyzed at pre-application, and 3, 6, and 12 hours after the protocol began.