Inclusion Criteria:  Inborn Preterm Neonates 26-34 weeks gestation admitted to NICU with diagnosis of RDS Babies who were initially started on High Flow Oxygen Therapy/nCPAP but unable to maintain saturation > 90% on fio2 of 40% in 1st 6 hours of life. Capillary PCO2 of > 70 or arterial PCO2 > 65 on two repeated sampling within 4 hours Neonates whose parents consented to participate.  Exclusion Criteria:  All preterm babies who are below < 26 weeks above the 34 weeks of gestation Preterm neonates (26-34 weeks) with diagnosis of RDS requiring endotracheal intubation within Labor room/Operation Theater or within 1st hour of life for respiratory support. Preterm Neonates with the gestational age of 26-34 weeks, diagnosed as congenital pneumonia or sepsis. Patient with poor respiratory drive due to any reason neurological or central causes Diaphragmatic hernia or any other thoracic anomaly Pleural effusion unilateral or bilateral Congenital cystic pulmonary malformation. Neonates with underlying cyanotic heart disease. Neonates with acynotic heart disease causing pulmonary edema Neonates with cleft lip and cleft palate or any other surgical condition.