Fig. 1

a Representative chest X ray of a COVID-19 patient on mechanical ventilation showing bilateral consolidations (red arrows). b Spiral CT scan of a representative COVID-19 patient indicating multiple bilateral patchy ground glass infiltration. c Red blood cells were preincubated with 5 mM of DAF for 20 min at 37 °C in PBS containing 1% BSA in the dark. Intracellular NO was determined by FACS analysis. A representative histograph from one out of 14 COVID-19 positive patients and 4 healthy controls is shown. d The mean fluorescent intensity (MFI) of all the subjects in each group is presented (*p < 0.05 using Student’s t-test). e Representative histogram of intracellular NO from RBCs of a single hypoxic non-COVID-19 patient