CRP and acute respiratory distress syndrome: Table 1 presents the demographic characteristics and baseline clinical characteristics. Among the included patients, 68 (73%) patients required endotracheal intubation, while 49 (53%) patients were diagnosed with direct lung injury. Sixty-eight patients (73%) had ARDS from infection. Compared with the other groups, the low ROX group showed a lower PaO2/FiO2 ratio for ARDS diagnosis, rate of endotracheal intubation, C-reactive protein levels, and PEEP, as well as a higher age and APACHE II scores on admission.