Lung ultrasonography cannot differentiate infectious pneumonia from aspiration pneumonitis in neonates: findings from a prospective multicenter study

Lung ultrasound (LUS) is being increasingly used to diagnose neonatal pneumonia. However, whether LUS can distinguish between infectious pneumonia (IP) and aspiration pneumonitis (AP), between ventilator-associated pneumonia (VAP) and non-VAP, or between meconium aspiration pneumonitis (MAP) and non-MAP remains unclear. Therefore, we conducted this prospective multicenter study to address these questions. This prospective multicenter study was conducted in five tertiary hospitals in China from November 2020 to June 2022. Neonates with a confirmed diagnosis of IP or AP were included. LUS examinations were performed using a standardized 12-region protocol. LUS findings were compared between IP and AP patients, between VAP and non-VAP patients, and between MAP and non-MAP patients. The major LUS imaging characteristics and complications were compared among the groups. A total of 233 neonates were included (195 with IP and 38 with AP; 71 with VAP, 124 with non-VAP; 21 with MAP, 17 with non-MAP). All patients (100%) exhibited lung consolidations and pleural line abnormalities and B‑lines were observed in 172 patients (74.0%). No significant differences in LUS manifestations were found between IP and AP, between VAP and non-VAP, or between MAP and non-MAP. LUS lacks specificity for distinguishing infectious pneumonia from aspiration pneumonitis in neonates, and it cannot differentiate between VAP and non-VAP or between MAP and non-MAP. The differential diagnosis of these conditions still requires integration of clinical history and relevant laboratory tests.