Synchronization allows that the cycles of inspiratory positive pressure provided by the ventilator coincide with the inspiratory effort, increasing the system efficacy. The Neurally Adjusted Ventilatory Assist (NAVA) is a mode of partial ventilatory support based on the use of electrical activity of the diaphragm (Edi) to control the mechanical ventilator. The ventilatory assistance starts according to respiratory needs of the patient, its use in very low birth weight infants showed an improvement in patient-ventilator interaction, even in the presence of leak around the endotracheal tube. This prospective randomized, clinical trial aims to evaluate, in preterm infants with gestational age lower than 34 weeks with respiratory failure treated with noninvasive ventilatory support, the impact of SNIPPV with neural adjustment (NAVA) on success ventilation and the need for endotracheal intubation when compared to treatment with traditional CPAP.