To Investigate the Effect of Pulmonary Surfactant With Different Inspired Oxygen Concentrations on the Clinical Outcomes of Very Preterm Infants Under Non-invasive Assisted Ventilation

A prospective multicenter randomized controlled study was conducted. Eligible very preterm infants with a gestational age of \<32 weeks were enrolled. All infants received routine treatment after birth and were randomly divided into two groups according to the FiO2 threshold of PS under noninvasive assisted ventilation: Control group (FiO2=0.30) and low concentration group (FiO2=0.25). Clinical data were collected to explore the differences in clinical outcomes between the two groups.

① All the very/extremely preterm infants who met the criteria were divided into low concentration group and high concentration group according to the random number table method. The pressure, respiratory rate and other parameters were set according to the relevant clinical guidelines or expert consensus. The initial FiO2 was 21% when PEEP was ≥6 cmH2O. To maintain SpO2 90%-94%. According to the FiO2 threshold corresponding to randomization, PS treatment was given when FiO2 reached the threshold (the initial dose was 200mg/kg, and the second or third dose of 100mg/kg could be repeated if necessary if the disease progressed). PS treatment was administered as early as possible within 6 hours after birth. Endotracheal intubation, INSURE technique, or LISA technique can be used. ② The basic information and perinatal outcomes of the two groups were collected; Outcome indicators: the main outcome indicators were the failure rate of non-invasive treatment, the time of tracheal intubation mechanical ventilation, the time of non-invasive assisted ventilation, the days of oxygen therapy, the time of the first use of PS, and the rate of repeated PS. The secondary outcomes included mortality, incidence of BPD, incidence of ROP, oxygen demand at 28 days after birth and 36 weeks of corrected gestational age, oxygen demand at discharge, length of hospital stay, and cost of hospitalization.