We added this information also in Table 3. We analysed FiO2 (depending on the method of oxygen delivery - nasal canulae, HNF, MV), as you suggested and the cut-off value of FiO2 corresponded to the cut-off for the oxygen flow rate, so the two groups in Table 3 would be similar.
Results The median oxygen flow rate is shown to be 14 L/min, but FiO2 may vary depending on the method of oxygen delivery (nasal canulae, HNF, MV).