Point-of-care lung ultrasound to differentiate bacterial and viral lower respiratory tract infections in pediatric age: a multicenter prospective observational study

Distinguishing between bacterial and viral etiologies in children with Lower respiratory tract infections (LRTIs) is challenging. This study investigates the association between lung Point-of-Care ultrasound (POCUS) characteristics and the etiologic diagnosis of LRTI. This multicenter, prospective, observational study included children admitted with suspected LRTI to three pediatric centers in Italy. Lung POCUS was performed within six hours of clinical diagnosis, alongside collection of clinical, laboratory, microbiological, and radiological data. Patients were stratified into groups based on presumed microbial etiology: bacterial pneumonia (confirmed or probable) and viral pneumonia (confirmed or probable). 162 children were admitted, 90 with viral pneumonia (74 confirmed, 16 probable), and 72 with bacterial pneumonia (15 confirmed, 57 probable). The lung POCUS score was higher in bacterial infections compared to viral ones (mean score of 32 vs. 27.5, p < 0.001). Receiver operating characteristic (ROC) curves showed that models incorporating POCUS (AUC = 0.88) or chest X-ray (CXR) findings (AUC = 0.89), along with a minimal amount of clinical and laboratory findings, were both accurate in establishing the pneumonia etiology. The study indicates that lung POCUS is a valuable tool that can support clinical and laboratory items in the diagnostic process of LRTI. These results also suggest that POCUS can be as effective as CXR in aiding diagnosis, providing solid evidence for a radiation-free alternative.