The nasal CPAP (continuous positive airway pressure), is a technique of noninvasive ventilation commonly used in neonatal intensive care units, and has recently been used in association with nasal intermittent mandatory ventilation (NIPPV - intermittent Nasal Positive Pressure Ventilation), which consists of the application of respiratory positive pressure cycles during the application of nasal CPAP, resulting in high pharyngeal pressures. The NIPPV has advantages over traditional CPAP, including the prevention of atelectasis, improved respiratory mechanics and decreased work of breathing in premature infants. A refinement of this technique is the use of positive pressure breaths associated with nasal CPAP synchronously in relation to the newborn's inspiratory effort (SNIPPV - Synchronized Nasal Positive Pressure Ventilation).