Expanded versus classical assessments for identifying mandate for lung ultrasound-guided surfactant therapy in preterm neonates (EXCLAIM-LUS): a retrospective comparative study.

UNLABELLED: Lung ultrasound (LUS) is increasingly used to guide surfactant therapy in preterm neonates with respiratory distress syndrome (RDS). To compare diagnostic performance of LUS scoring systems with various partitioning for predicting surfactant requirement in preterm neonates with RDS. Retrospective observational study. Preterm neonates (≤ 34 weeks) with RDS who underwent LUS within two hours of admission were included. Images were independently scored using four protocols: 6-area anterolateral (A/L), 6-area anterolateral-posterior (A/L/P), 10-area, and 12-area. All four scoring systems demonstrated good discrimination for surfactant requirement (AUC 0.800-0.831), with no statistically significant pairwise differences (all p ≥ 0.19). Decision curve analysis (DCA) confirmed positive net benefit for all protocols at threshold probabilities of 10-55%. CONCLUSIONS: All four LUS scoring systems demonstrated comparable performance. Classical 6-area anterolateral protocol may be considered a pragmatic choice given its simplicity and comparable performance for routine LUS-guided surfactant therapy in preterm RDS. WHAT IS KNOWN: • LUS predicts surfactant need in preterm RDS (AUC 0.84-0.97). • Multiple scoring systems with varying zone counts exist but direct comparative evidence is lacking. WHAT IS NEW: • All four protocols (6-area anterolateral, 6-area Anterolateroposterior, 10-area eLUS, and 12-area) show comparable diagnostic performance (AUC 0.800-0.831) with overlapping decision curve net benefit. • The 6-area anterolateral protocol achieves equivalent utility with the lowest procedural burden.