amiodarone; antibiotic agent; dexamethasone; gallium; oxygen; prednisone; abnormal respiratory sound; acute hypoxemic respiratory failure; adult; aged; ambient air; atrial fibrillation; case study; community acquired pneumonia; complication; computer assisted tomography; conference abstract; coronavirus disease 2019; crackle; diagnosis; drug combination; drug therapy; drug toxicity; dyspnea; female; fever; high risk population; human; in vitro study; leukocytosis; lung biopsy; lung disease; lung injury; lung toxicity; nonhuman; pandemic; pneumonia; prevention; prognosis; public health; pulse oximetry; scintigraphy; Severe acute respiratory syndrome coronavirus 2; spike; thorax radiography; very elderly