A Refined Score, Namely Thoracic Ultrasound Score, to Predict the Need for Surfactant in Preterm Neonates: A Prospective, Multicenter, Observational Study

Introduction: Lung ultrasound score (LUS) is used to predict the need for surfactant in preterm neonates. Its performance is lower in neonates with a gestational age (GA) ≥ 34 weeks. We developed a score, thoracic ultrasound score (TUS), to overcome the shortcomings of LUS. Objectives: To assess the feasibility and diagnostic accuracy of TUS to evaluate oxygenation and predict the need for surfactant administration, compared to LUS. Materials and methods: This was a prospective, multicenter, observational study. Preterm neonates in noninvasive ventilation with GA between 24 + 0 and 36 + 6 weeks were assessed for eligibility. Lung ultrasound were performed within 3 h of life, and TUS and LUS were calculated. Results: Fifty-eight neonates who received surfactant were compared with 112 neonates who did not receive surfactant: GA 30.2 ± 3.1 weeks versus 32.6 ± 2.3 weeks, (p < 0.001), and birth weight 1466 ± 674 g versus 1725 ± 519 g, (p = 0.006), respectively. TUS and LUS showed a similar association with S/F ratio (r = -0.670 and r = 0.615) and OSI (r = 0.524 and r = 0.423), all p < 0.001. In neonates with GA < 34 weeks, the AUC (95% CI) was similar: 0.956 (0.923-0.989) versus 0.952 (0.921-0.984). In neonates with GA ≥ 34 weeks, the AUC (95% CI) of TUS was superior to LUS: 0.971 (0.914-1.000) versus 0.797 (0.639-0.980), p = 0.02. Conclusion: Compared to LUS, TUS showed a similar association with the oxygenation status and a superior ability to predict the need for surfactant in neonates with GA ≥ 34 weeks. The latter was similar in neonates with GA < 34 weeks.