Prospective, Non-Blinded, Randomized Controlled Trial on Early Administration of Pulmonary Surfactant Guided by Lung Ultrasound Scores in Very Preterm Infants.

Ultrasound group: Lung ultrasonography will be performed within 1 h of admission, followed by lung ultrasound scoring. If the lung ultrasound confirms RDS and LUS is more than 8, a full dose of PS will be promptly administered at 200 mg/kg (Poractant Alfa, Curosurf®). If the lung ultrasound does not indicate RDS or if LUS is 8 or less, clinical monitoring will continue. Should the clinical criteria for NRDS be met, a full dose of PS will be administered at 200 mg/kg (Poractant Alfa, Curosurf®). Lung ultrasound and scoring will be repeated 4 to 10 h post the first PS dose administration. Repeated PS administration will occur if the criteria are met, with lung ultrasound scoring conducted prior to each administration. Control group: In cases where clinical diagnosis confirms NRDS, PS will be administered at a dosage of 200 mg/kg (Poractant Alfa, Curosurf®). If clinical manifestations do not meet the diagnosis of NRDS, PS will not be administered. All enrolled infants will undergo lung ultrasound scoring at 24 h, 3 days, 7 days, 14 days, 28 days, and 36 weeks CA (prior to discharge).