NAVA Use in Preterm Neonates With Respiratory Distress Syndrome

Inclusion Criteria: 1. Gestational age ≤ 34 weeks. 2. Neonates that have RDS according to clinical and radiological findings 3. Neonates requiring invasive mechanical ventilation. Exclusion Criteria: * 1\) Preterm neonates that have respiratory distress due to causes other than respiratory distress syndrome including transient tachypnea of new born , congenital pneumonia and sepsis. 2)Central and peripheral conditions that limit the respiratory drive, as well as diaphragmatic anatomical defects in patients with an intact respiratory drive, comprise the contraindications to NAVA * Examples are the following: * Central disorder: paralytic drug use, respiratory drive suppression due to heavy sedation or brain injury. * Peripheral disorder: phrenic nerve injury, paralytic agent administration. * Structural (anatomical) disorder: esophageal atresia, diaphragmatic hernia. 3) Cardiac patients including aortic coarctation , double outlet right ventricle (DORV), Tetralogy of Fallot and Transposition of the great arteries (TGA). 4) Surgical patients including gastroschisis , omphalocele , tracheoesophageal fistula and congenital diaphragmatic hernia (CDH).