Semi-quantitative chest-CT severity score predicts failure of non-invasive positive pressure ventilation in people hospitalized for COVID-19 pneumonia: Short title: CT score in COVID-19 pneumonia

Abstract Objective Non-invasive positive pressure ventilation (NPPV) emerged as an efficient tool for treatment of Coronavirus disease-19 (COVID-19) pneumonia. The factors influencing NPPV failure are still elusive. The aim of the study was to investigate the relationships between semiquantitative chest computed tomography (CT) scoring and NPPV failure and mortality in patients with COVID-19 Design Observational study Setting Non-intensive setting of care Participants N=112 patients consecutively admitted for COVID-19 pneumonia. Interventions Usual care including various degrees of respiratory support Measurements and Main Results The semi-quantitative CT-score was calculated at hospital admission. Subgroups were identified according to the ventilation strategy used (oxygen delivered by Venturi mask n=53; NPPV-responder n=38; NPPV-failure n=21). The study's primary endpoint was the use of NPPV. The secondary endpoints were NPPV failure and in-hospital death, respectively. CT-score progressively increased among groups (6 vs 9 vs 14, p Conclusions We reported the common and effective use of NPPV in patients with COVID-19 pneumonia. In our population, a semi-quantitative chest CT analysis at hospital admission accurately identified those people poorly responding to NPPV.