Prognostic value of lung ultrasound score performed in the Emergency Department in COVID-19 patients: a prospective multicenter study in central Italy

Lung ultrasound (LUS) is an essential tool for respiratory disease differential diagnosis at Emergency Department (ED), due to easy applicability and safety. During Sars-Cov 2 pandemic, LUS was widely used in every setting. This study aims to demonstrate the prognostic role of LUS independently of other factors and the identification of an LUS score cut-off to be applied in the ED. A multi-center prospective study was conducted on 285 patients, 123 from Pisa University Hospital, 162 from S. Maria Misericordia Hospital of Perugia. All patients received LUS examination by expert sonographers within 48 hours of admission with the same methodology. Univariate logistic analysis demonstrated that LUS is a mortality predictor, OR 2.8 (CL1.5-5.1). Using LUS score cut-off 1.3, the OR was 6.7 (CL2.7-1.6). In multivariate logistic analysis, LUS score significantly predicted death, independently of other factors. ROC curves comparison demonstrated that the introduction of LUS score <1.3 to a multifactorial model improved the association with mortality (AUC 0.76vs0.84, p=0.04). LUS combined with clinical, anamnestic, laboratory, and blood gas parameters, would allow an effective prognostic stratification in Sars-Cov2 patients at ED.