Respiratory distress syndrome (RDS) is a common cause of respiratory failure in preterm infants and is frequently treated with surfactant therapy. With the increasing use of noninvasive ventilation, less invasive methods of surfactant administration have been developed. In the technique known as Less Invasive Surfactant Administration (LISA), surfactant is delivered into the trachea through a thin catheter, without the need for endotracheal intubation. This approach may reduce lung injury and improve respiratory outcomes in spontaneously breathing preterm infants. This multicenter, prospective, randomized study aims to compare the clinical effectiveness of poractant alfa and calfactant when administered using the LISA technique in preterm infants born at less than 30 weeks' gestation with RDS who are not intubated. The study will evaluate short-term outcomes, including the need for intubation, repeat surfactant administration, and respiratory support during the first 72 hours of life, as well as longer-term outcomes such as bronchopulmonary dysplasia and other neonatal morbidities.

Respiratory distress syndrome (RDS) remains one of the leading causes of respiratory failure in preterm infants. Surfactant replacement therapy is a cornerstone of RDS management; however, traditional administration through endotracheal intubation and mechanical ventilation may contribute to ventilator-induced lung injury and increase the risk of adverse pulmonary outcomes. With the widespread adoption of non-invasive respiratory support strategies, less-invasive approaches to surfactant administration have gained increasing attention.

Less Invasive Surfactant Administration (LISA) is a technique in which surfactant is delivered directly into the trachea via a thin catheter under direct laryngoscopic visualization. At the same time, the infant continues to breathe spontaneously on noninvasive respiratory support. This method avoids endotracheal intubation and mechanical ventilation and has been associated with reduced need for invasive ventilation and improved respiratory outcomes in preterm infants.

Several surfactant preparations are currently used in neonatal practice. Poractant alfa and calfactant are two commonly administered natural surfactants with differing biochemical composition and dosing characteristics. Although both agents are widely used for the treatment of RDS, data directly comparing their effectiveness when administered via the LISA technique are limited.

This multicenter, prospective, randomized study is designed to compare the clinical efficacy of poractant alfa and calfactant administered using the LISA technique in preterm infants with respiratory distress syndrome. Eligible participants will be preterm infants born at less than 30 weeks' gestation, diagnosed with RDS based on clinical and radiographic criteria, who are spontaneously breathing and receiving noninvasive respiratory support without prior endotracheal intubation.

After enrollment, infants will be randomly assigned to receive either poractant alfa or calfactant via the LISA method. In both groups, surfactant will be administered through a thin catheter inserted into the trachea under direct laryngoscopic visualization while maintaining spontaneous breathing and noninvasive respiratory support. Standard neonatal intensive care practices will be applied throughout the study period in all participating centers.

The primary focus of the study is to compare short-term respiratory outcomes between the two treatment groups. These include the need for endotracheal intubation, the requirement for repeat surfactant administration, and the level and duration of respiratory support within the first 72 hours of life. Secondary outcomes include longer-term clinical outcomes such as the development of bronchopulmonary dysplasia at 36 weeks' postmenstrual age, as well as other neonatal morbidities, including intraventricular hemorrhage, necrotizing enterocolitis, and overall survival to discharge.

By directly comparing poractant alfa and calfactant administered via the LISA technique in a randomized, multicenter setting, this study aims to provide evidence on the optimal surfactant choice for less invasive treatment of RDS in very preterm infants. The findings are expected to inform clinical practice and contribute to the improvement of respiratory management strategies.

Inclusion Criteria:

• Born at a participating study center hospital.
• Gestational age between 24 1/7 and 29 6/7 weeks (<30 0/7 weeks).
• Postnatal age within the first 6 hours of life.
• Being on non-invasive respiratory support.
• Presence of clinical and radiological findings consistent with respiratory distress syndrome (RDS).
• Indication for surfactant therapy defined as a requirement for FiO₂ >30% to achieve target oxygen saturation (SpO₂ 90-94%) while receiving noninvasive respiratory support with a minimum pressure of 6 cmH₂O.
• Written informed consent obtained from a parent or legal guardian.

Exclusion Criteria:

• Infants who were intubated for any reason before the decision to administer surfactant.
• Severe birth asphyxia, defined as the need for advanced resuscitation after birth, 10th minute Apgar score ≤5, and arterial blood gas within the first hour of life showing pH <7.0 and base excess (BE) ≤-12.
• Presence of major congenital anomalies.
• Respiratory distress due to causes other than respiratory distress syndrome (RDS).
• Congenital heart disease.
• Congenital diaphragmatic hernia.
• Pulmonary hypoplasia.
• Chromosomal abnormalities.
• Presence of pneumothorax.
• Lack of informed consent.
• Neonatal seizures presence.
• Postnatal age greater than 6 hours.
• Infants born outside of gestational weeks 24 1/7 - 29 6/7.
• Requirement for invasive mechanical ventilation at enrollment.
• Infants receiving noninvasive respiratory support with an FiO₂ requirement <0.30.

I am not authorized to share patient data.