Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia

Background Lung ultrasound (LUS) is widely used in the management of neonatal pneumonia, our previous research has confirmed that LUS cannot identify the etiologies of neonatal pneumonia. However, there is still controversy and confusion regarding whether LUS can differentiate between different types of pneumonia (such as intrauterine infectious pneumonia (IP), ventilator-associated pneumonia (VAP), community-acquired pneumonia (CAP), meconiumaspiration pneumonia (MAP)). Therefore, we have organized this prospective multicenter study to address and answer these remaining questions. Methods A prospective approach was used to collect LUS data on neonatal all kinds of pneumonia from 5 tertiary hospitals in China. The patients were devided into three categories: based on whether there is evidence of infection,ventilator treatment ot the history of meconium aspiration, they are classified as IP and non-IP, VAP and non-VAP, MAP and non-MAP. The major LUS imaging characteristics and complications were compared among groups. Results A total of 235 patients with neonatal pneumonia were included, comprising 195 patients with IP and 40 patients with non-IP. The ultrasound characteristics included pleural line abnormalities in all 235 patients, involving zones 1–12;B-lines in 174 patients, involving zones 1–12;lung consolidation in all 235 patients, involving zones 1–12%; pneumothorax in 4 patients; and pleural effusion in 31 patients.No significant differences in ultrasound characteristics were found between patients with MAP and patients with non-MAP or between patients with-or without VAP.Compared with IP,aspiration pneumonia was associated with a significantly greater incidence of right lung consolidation (100% vs. 89.2%),with no significant differences in other ultrasound signs. Conclusion The results of this study show that the most common ultrasound imaging manifestations of various etiologies of pneumonia in newborns are lung consolidation accompanied by airbronchograms.Differentiating between various types of pneumonia still requires the combination of medical history and relevant laboratory tests.