Primary outcome:
ROX indexes at H0 and H1, and their changes during the first hour were not different according to HFNC failure or success (Table 1). Their respective AUC were 0.56 (95% CI 0.48-0.63, p =0.14), 0.56 (95% CI 0.49- 0.64, p =0.09), and 0.54 (95% CI 0.45-0.62, p =0.34) (Table 2). These results didn’t support that early ROX indexes predicted HFNC failure.