Preterm neonates usually develop respiratory distress syndrome (RDS) for which they need respiratory support, which may be invasive and non-invasive depend on the availability and individual need. Non-invasive is relatively safe but non-invasive high frequency oscillatory ventilation (nHFOV) is not appropriately evaluated in neonates as primary support. So the investigators hypothesized that nHFOV is relatively safe and effective in comparison with invasive ventilation for preterm neonates with RDS.

Respiratory distress is a common morbidity in preterm neonates that requires respiratory support and surfactant replacement, if not adequately and timely managed may cause multi-organ dysfunction. Respiratory support can be delivered via both non-invasive (NIV) and invasive mode depending upon the availability of ventilators ,experience and comfort level of physician, and availability of department protocol.

Non-invasive ventilation include CPAP (Continuous Positive Airway Pressure), NIPPV (Non-invasive Positive Pressure Ventilation) and nHFOV (Non-invasive High Frequency Oscillatory Ventilation). Non-invasive ventilation is currently the preferred mode of ventilation globally due to its safety profile, early weaning, less barotrauma, volume trauma and other complications.

Literature review reveals reported comparison for some non-invasive modes of ventilation like CPAP and NIPPV versus conventional ventilation however other non-invasive modes such as nHFOV have still not been appropriately evaluated. nHFOV provides 60-1200 breath/minute with minimal tidal volume while keeping the lungs expanded with equal distribution of air in whole lung so less chances of barotrauma and volutrauma. Extra pressure which is not needed by the lung is dissipated through oral cavity and esophagus to the stomach. Few observational studies reported that extubation failure is better prevented with utilization of NHFOV.

For preterm neonates with RDS nHFOV compared with nCPAP showed better results in term of short duration of intervention, less chances of failure, low incidence of intraventricular hemorrhage, and other respiratory complications were almost equal.

A multicenter double, blinded, randomized controlled trial is under process for using non-invasive ventilation to prevent extubation failure. Another randomized controlled cross over trial performed in a small number of extreme preterm does showed better clearance of carbon dioxide with nHFOV compared with CPAP.

Retrospective cohort study published recently evaluating the use of non-invasive ventilation (nCPAP, SNIPPV and nHFOV) for preterm neonates with RDS, showed satisfactory outcomes with nHFOV with fewer babies requiring invasive ventilation.

A metanalysis of Randomized Controlled Trials of studies evaluating the use of nHFOV, nCPAP and biphasic CPAP; published recently showed nHFOV to be more effective as compared to other modes. The primary outcome of the RCT included in the meta analysis was decreased chances of intubation and better clearance of carbon dioxide.

In this study investigators will include inborn preterm neonates with no antenatal, perinatal risk factor or anomalies that can affect the outcome. Those babies who developed respiratory distress syndrome at birth and does not need early invasive ventilation will be recruited in study. Study will be conducted in almost 10 centers in Pakistan and Russia, total 1200 babies will be included from all centers. After all teaching and training regarding management strategies and equipment utilization. Recruited participants will be further divided in two arms, one in intervention arm (nHFOV) and other is control arm (Invasive Conventional) ventilation. Outcome will be assessed for respiratory support, surfactant requirement, duration of respiratory support, response to therapy and complications related to respiratory support.

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.

In order to maintain data confidentiality, it will not be shared with other researcher