Lung injury in patients with or suspected COVID-19 : a comparison between lung ultrasound and chest CT-scanner severity assessments, an observational study

BackgroundChest CT (CT) is the reference for assessing pulmonary injury in suspected or diagnosed COVID-19 with signs of clinical severity. We explored the role of lung ultrasonography (LU) in quickly assessing lung status in these patients. MethodseChoVid is a multicentric study based on routinely collected data, conducted in 3 emergency units of Assistance Publique des Hopitaux de Paris (APHP); 107 patients were included between March 19, 2020 and April 01, 2020 and underwent LU, a short clinical assessment by 2 emergency physicians blinded to each others and a CT. LU consisted of scoring lesions in 8 chest zones from 0 to 3, defining a severity global score (GS) ranging from 0 to 24. CT severity score ranged from 0 to 3 according to the extent of interstitial pneumonia signs. 48 patients underwent LU by both an expert and a newly trained physician. FindingsThe GS showed good performance to predict CT severity assessment of COVID-19 as normal versus pathologic: AUC=0.93, maximal Youden index 1 with 95% sensitivity, and 83% specificity. Similar performance was found for CT assessment as normal or minimal versus moderate or severe (n=90): AUC 0.89, maximal Youden index 7 with 86% sensitivity, and 78% specificity. Good agreement was found for zone scoring assessed by new trainee (30mn theory + 30mn practice) and expert (n=14,14*8 checkpoints), weighted kappa 0.85-1; moderate agreement was found for new trainee (n=48, 30mn theory) and expert, kappa 0.62-0.81. InterpretationGS score is a simple tool to assess lung damage severity in patients with suspected or diagnosed COVID-19. Comparing the performance of new trainees and expert physicians opens a path for adoption beyond the scope of experts. LU is a good candidate for patients triage, especially in case of CT availability issues.