Neonatal respiratory distress syndrome (RDS) is the most common cause of respiratory failure in the first few days in life. It is characterized by the tendency of alveoli and terminal bronchioles to collapse due to the lack of surfactant. RDS is inversely related to gestational age and remains a dominant clinical problem encountered among preterm infants.

The reduction in tidal volume secondary to alveolar collapse may result in alveolar derecruitment, cyclic opening and closing of atelectatic alveoli and distal small airways leading to inflammation and lung injury). On the other hand, the use of high positive end expiratory pressure (PEEP) may be associated with excessive lung parenchyma strain and unfavorable hemodynamic effects. Therefore, lung recruitment maneuvers have been proposed and used to open collapsed lung while managing with low pressure PEEP. However, the best recruitment maneuver technique is currently unknown.

Proinflammatory cytokines are synthesized by alveolar macrophages, type II pneumocytes and other local pulmonary cells causing inflammation that starts a cascade leading to lung injury. Nevertheless, they are released systemically and can lead to injury of other organs.

This study aims to measure inflammatory cytokines in the serum of premature infants who receive and do not receive sustained lung inflation. The study hypothesis is that, in premature infants supported with CPAP, the use of sustained inflation is associated with decreased inflammatory biomarkers and improved respiratory outcomes.

The study includes infants with gestational age of 28-24 weeks during the first 6 hours of life who will be randomly assigned to either receive (or do not receive) sustained inflations. Serum concentrations of cytokines (IL-6, IL-8, IL-1β and TNF-α) will be measured at enrollment and at 96 hours. The primary outcome of this study will be the change in serum cytokine concentrations after intervention in both groups. Clinical respiratory outcomes will be monitored.

Inclusion Criteria:

1. Gestational age between 28 weeks (and 0 days) and 34 weeks (and 6 days)
2. Postnatal age <6 hours
3. Respiratory distress syndrome diagnosed by both clinical findings of subcostal retractions, tachypnea (>70 breaths/min), the need for respiratory support to maintain oxygen saturation > 87% and X-ray findings of RDS
4. Application of early CPAP <6 hours of age
5. Oxygen requirement (FiO2 >30% to maintain preductal saturation 87% - 93%)

Exclusion Criteria:

• Before enrollment: infants will not be considered in the study if any of the following conditions exists: major congenital anomalies, severe hemodynamic instability indicative of early septicemia, use of inotropes, severe metabolic acidemia with base deficit >12 mEq/dl, frequent apnea / bradycardia (6 episodes per day with HR <100 or 2 episodes per day with HR<60 requiring bag-and-mask ventilation), maternal chorioamnionitis (fever >38 degree Celsius with abdominal tenderness) and PPROM >18 hours, and perinatal hypoxia (Apgar score < 6 at 5 minutes)
• After enrollment: infants will be eliminated from the study if the initial blood culture on admission is positive.

All laboratory testing will be performed by investigators who are not aware of group assignment.