This study aimed to investigate the clinical efficacy and safety of different non-invasive respiratory support methods in preterm infants with respiratory distress syndrome (RDS) after extubation. Methods: From Oct 2017 to 2018, 120 preterm infants were recruited from the NICUs of three hospitals. They were diagnosed with RDS and required mechanical ventilation. After extubation from mechanical ventilation, these infants were divided into NCPAP group, SNIPPV group and SNIPPV + NCPAP group. The time of non-invasive ventilation, reintubation rate within 72 h, success rate of non-invasive ventilation within 1 week, duration of oxygen therapy, hospital stay and incidence of complications were recorded and compared. Results: Compared with the NCPAP group, the SNIPPV group and the SNIPPV + NCPAP group had significantly higher rate of successful extubation and removal from non-invasive ventilation within 1 week (P < 0.05). There were no significant differences among three groups in the time of non-invasive ventilation, time of oxygen therapy, hospital stay or incidence of complications (P > 0.05). Conclusion: SNIPPV + NCPAP after mechanical ventilation is a relatively safe and effective ventilation strategy for preterm infants with severe RDS. The use of NCPAP facilitates the turnover of SNIPPV ventilators in developing countries.

Background: The failure rate of noninvasive ventilation (NIV) remains high in patients with acute respiratory distress syndrome (ARDS). The etiology of ARDS may play an important role in NIV failure.Methods: A multicenter prospective observational study was performed in 17 ICUs in China from September 2017 to December 2019. ARDS patients who used NIV as a first-line therapy were enrolled. The etiology of ARDS was recorded at study entry. Results: A total of 306 patients were enrolled. Of the patients, 146 were classified as having pulmonary ARDS (ARDSp) and 160 were classified as having extrapulmonary ARDS (ARDSexp). NIV improved PaO2/FiO2 from initiation to 24 h of NIV in both groups. However, it improved more slowly in patients with ARDSp than in those with ARDSexp (interaction effect: p < 0.01). ARDSp patients experienced more NIV failure (55% vs. 28%; p < 0.01) and higher 28-day mortality (47% vs. 14%; p < 0.01). The multivariate Cox regression also showed that ARDSp was independently associated with NIV failure (hazard ratio [HR] = 2.81, 95% confidence interval [CI]: 1.89-4.18) and 28-day mortality (HR = 7.49, 95% CI: 4.32-13.01). After propensity matching, 62 patients remained in each group. The baseline data were comparable between the two groups. ARDSp was still independently associated with NIV failure and 28-day mortality (HR = 2.62, 95%CI: 1.49-4.61; and 5.70, 2.59-12.55, respectively). Sensitivity analysis also confirmed these results. Conclusions: Among ARDS patients who used NIV as a first-line therapy, ARDSp was associated with slower improvement in oxygenation, more NIV failure, and higher 28-day mortality than ARDSexp.