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

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.