Study design
Ethical approval of this monocentric retrospective study was delivered by the review board of our hospital (Hospitals of Tours, François Rabelais University, France). From March 19th to April 28th 2020, we included 349 patients either suspected of COVID-19 infection or previous RT-PCR COVID-19 positive patients to whom a chest CT scan was performed in the radiology department.
Inclusion criteria were: clinical suspicion of COVID-19 infection with severe symptoms requiring hospitalization or other comorbidities listed below : patients previously hospitalized for another reason and suspected of COVID-19 infection, patients with initial negative RT-PCR presenting a clinical deterioration during their hospitalization.
Comorbidities were : age > 65 years, chronic respiratory disease, dialysis, cardiac insufficiency NYHA 3 or 4, history of cardiac diseases (arterial hypertension, coronaropathy, stroke, cardiac surgery), cirrhosis (≥ Child B), diabetes with complications or requiring insulin therapy, immunosupression (chemotherapy, biotherapy, immunosuppressive corticotherapy, uncontrolled HIV or CD4 < 200/mm3, metastatic cancer, all types of graft), BMI > 40, or pregnancy. Clinical severity scale was assessed according to the Chinese Center of Disease Control and Prevention : uncomplicated illness (upper respiratory tract damages, including mild fever, cough (dry), sore throat, nasal congestion, headache, myalgia, or malaise. Symptoms of a more serious disease, such as dyspnoea, are not present), moderate pneumonia with dyspnoea, severe pneumonia (Sp02 < 90 % in ambient air, tachypnoea > 30/min), and acute respiratory distress syndrome (clinical and ventilation criteria : mild acute respiratory distress syndrome (ARDS) = 200 mmHg < PaO2/FiO2 ≤ 300 mmHg (positive PEEP or CPAP ≥ 5 mmHg if not ventilated or non-invasive ventilation)), moderate ARDS = 100 mmHg < PaO2/FiO2 ≤ 200 mmHg, and severe ARDS = PaO2/FiO2 ≤ 100 mmHg).16,17