This study aimed to investigate whether using lung ultrasound (LUS) scores in premature newborns with respiratory distress syndrome (RDS) allows for earlier surfactant therapy (within the first 3 h of life) than using FiO 2 criteria. This was a randomised, non-blinded clinical trial conducted in a neonatal intensive care unit. The inclusion criteria were newborns with a gestational age of ≤ 32 weeks and RDS. Patients meeting the inclusion criteria were randomly assigned to two groups: the ultrasound group, administered surfactant based on LUS score and/or FiO 2 threshold, and the control group, guided by FiO 2 only. Fifty-six patients were included. The ultrasound group received surfactant earlier (1 h of life vs. 6 h, p < 0.001), with lower FiO 2 (25% vs. 30%, p = 0.016) and lower CO 2 (48 vs. 54, p = 0.011). After surfactant treatment, newborns in the ultrasound group presented a greater SpO 2 (p = 0.001) and SpO 2 /FiO 2 ratio (p = 0.012). Conclusions: LUS score allowed an earlier surfactant therapy, reduced oxygen exposure early in life and a better oxygenation after the treatment. This early surfactant replacement may lead to reduced oxygen exposure. Keywords Lung ultrasound. Respiratory distress syndrome. Premature newborns. Surfactant Abbreviations CXR Chest X-ray GA Gestational age LUS Lung ultrasound NA Neonatologist-assistant nCPAP Nasal continuous positive airway pressure What is Known: • Lung ultrasound scores predict the need for surfactant therapy in premature newborns. What is New: • This study shows that using lung ultrasound scores improves the timeliness of surfactant replacement compared with using FiO 2 alone.

Background Bronchiolitis is the most common viral infection of the lower respiratory tract in infants under 2 years of age. The aim of this study was to analyze and compare the seasonal bronchiolitis peaks before and during the SARS-CoV-2 pandemic. Methods Descriptive, prospective, and observational study. Patients with severe bronchiolitis admitted to the Pediatric Intensive Care Unit (PICU) of a referral tertiary hospital between September 2010 and June 2021 were included. Demographic data were collected. Viral laboratory-confirmation was carried out. Each season was analyzed and compared. The daily average temperature was collected. Results 1116 patients were recruited, 58.2% of them males. The median age was 49 days. Respiratory syncytial virus (RSV) was isolated in 782 cases (70.1%). In April 2021, the first and only case of bronchiolitis caused by SARS-CoV-2 was identified. The pre- and post-pandemic periods were compared. There were statistically significant differences regarding: age, 47 vs. 73 days (p = 0.006), PICU and hospital length of stay (p = 0.024 and p = 0.001, respectively), and etiology (p = 0.031). The peak for bronchiolitis in 2020 was non-existent before week 52. A delayed peak was seen around week 26/2021. The mean temperature during the epidemic peak was 10ºC for the years of the last decade and is 23ºC for the present season. Conclusion The COVID-19 pandemic outbreak has led to a clearly observable epidemiological change regarding acute bronchiolitis, which should be studied in detail. The influence of the environmental temperature does not seem to determine the viral circulation.

Background The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has collapsed health systems worldwide. In adults, the virus causes severe acute respiratory distress syndrome (ARDS), while in children the disease seems to be milder, although a severe multisystem inflammatory syndrome (MIS-C) has been described. The aim was to describe and compare the characteristics of the severe COVID-19 disease in adults and children. Methods This prospective observational cohort study included the young adults and children infected with SARS-CoV-2 between March–June 2020 and admitted to the paediatric intensive care unit. The two populations were analysed and compared focusing on their clinical and analytical characteristics and outcomes. Results Twenty patients were included. There were 16 adults (80%) and 4 children (20%). No mortality was recorded. All the adults were admitted due to ARDS. The median age was 32 years (IQR 23.3–41.5) and the most relevant previous pathology was obesity (n = 7, 43.7%). Thirteen (81.3%) needed mechanical ventilation, with a median PEEP of 13 (IQR 10.5–14.5). Six (37.5%) needed inotropic support due to the sedation. Eight (50%) developed a healthcare-associated infection, the most frequent of which was central line-associated bloodstream infection (n = 7, 71.4%). One patient developed a partial pulmonary thromboembolism, despite him being treated with heparin. All the children were admitted due to MIS-C. Two (50%) required mechanical ventilation. All needed inotropic support, with a median vasoactive-inotropic score of 27.5 (IQR 17.5–30). The difference in the inotropic requirements between the two populations was statistically significant (37.5% vs. 100%, p < 0.001). The biomarker values were higher in children than in adults: mid-regional pro-adrenomedullin 1.72 vs. 0.78 nmol/L (p = 0.017), procalcitonin 5.7 vs. 0.19 ng/mL (p = 0.023), and C-reactive protein 328.2 vs. 146.9 mg/L (p = 0.005). N-terminal pro-B-type natriuretic peptide and troponins were higher in children than in adults (p = 0.034 and p = 0.039, respectively). Conclusions Adults and children had different clinical manifestations. Adults developed severe ARDS requiring increased respiratory support, whereas children presented MIS-C with greater inotropic requirements. Biomarkers could be helpful in identifying susceptible patients, since they might change depending on the clinical features.