LISA vs Endotracheal Surfactant in Preterm Neonates: A Lung Ultrasound Distribution Study

A Prospective Pilot Controlled Trial Comparing the Intrapulmonary Distribution of Exogenous Surfactant Between (LISA) and Conventional Endotracheal Intubation in Preterm Neonates With RDS Using Lung Ultrasound and the NOVEL Surfactant Distribution Homogeneity Index (SDHI)

This prospective, non-randomized, unblinded pilot study evaluates and compares the intrapulmonary distribution of exogenous surfactant in preterm neonates when administered via Less Invasive Surfactant Administration (LISA) versus conventional endotracheal intubation (ETT). Lung ultrasound (LUS) will be utilized to assess the pioneer Surfactant Distribution Homogeneity Index (SDHI) to quantify the evenness and extent of surfactant-induced lung aeration. Secondary objectives include evaluating changes in LUS scores, short-term clinical respiratory outcomes, and feasibility parameters for guiding future larger-scale trials.

Respiratory Distress Syndrome (RDS) is a primary cause of neonatal morbidity, typically managed with exogenous surfactant. While LISA has emerged as a preferred method to avoid mechanical ventilation, the comparative homogeneity of surfactant distribution remains unclear. This pilot study enrolls 22 infants (1:1 allocation) in a tertiary-level Neonatal Intensive Care Unit (NICU). The experimental group receives surfactant via a thin catheter while on non-invasive support, whereas the active comparator group receives surfactant via an endotracheal tube. High-frequency linear probe lung ultrasounds are performed immediately before and 60 minutes post-administration across 12 lung regions. The primary metric, the genuine Surfactant Distribution Homogeneity Index (SDHI), is calculated from regional LUS score changes to assess aeration uniformity.

Inclusion Criteria:

Gestational age 24+0 to 42+6 weeks. Clinical and radiographic diagnosis of Respiratory Distress Syndrome (RDS). Requirement for surfactant within the first 3 days of life. Written informed parental consent.

Exclusion Criteria:

Infants intubated at birth or who received surfactant prophylactically in the delivery room.

Major congenital anomalies or lung malformations (e.g., congenital diaphragmatic hernia, pulmonary hypoplasia).

Syndromic or genetic conditions affecting lung or chest wall development. Severe hemodynamic instability or congenital heart disease requiring intensive support.

Lack of parental consent for trial participation.