Clinical Characteristics and Outcomes are Similar in ARDS Diagnosed by SpO2/FiO2 Ratio compared with PaO2/FiO2 Ratio.

SpO2/FiO2 ratio (SF) is highly correlated with the PaO2/FiO2 ratio (PF) in patients with acute respiratory distress syndrome (ARDS). However, it remains uncertain whether SF can be substituted for PF for diagnosis of ARDS and whether SF might identify patients who are systemically different from patients diagnosed by PF.