The Correlation between Partial Pressure of Oxygen/Fractional Inspired Oxygen and Peripheral Oxygen Saturation/Fractional Inspired Oxygen Ratio in Coronavirus Disease 2019-induced Acute Respiratory Distress Syndrome patients: A Retrospective Observational Study

Objective: The arterial partial pressure of oxygen (PaO 2 )/fractional inspired oxygen (FiO 2 ) (P/F) is the gold standard for assessing oxygenation; however, peripheral oxygen saturation (SpO 2 )/FiO 2 (S/F) also offers a noninvasive alternative. This study investigates the correlation between P/F and S/F ratio in coronavirus disease 2019 (COVID-19)-induced acute respiratory distress syndrome (ARDS) patients. Materials and Methods: A retrospective observational study design was followed from April 2020 to December 2020 in a tertiary hospital in Jeddah, Saudi Arabia. The patients diagnosed with COVID-19-induced ARDS were using the Berlin criteria. Descriptive statistics, Pearson’s correlation coefficient, and the receiver operating characteristic (ROC) curve were used to describe relevant outcomes. Results: Among 108 patients, 85 had ARDS based on X-rays. A strong, significant, and positive correlation was observed between P/F and S/F ratios ( r = 0.752, P < 0.001). The median P/F and S/F ratio was 77.78 and 108.01, with a significant difference ( P = 0.001) and Z -statistics of 3.44 for S/F and 3.47 for P/F ratio. The area under the ROC curve (AUC) for P/F and S/F was 0.69 (95% confidence interval [CI]: 0.60–0.78), and 0.69 (95% CI: 0.59–0.78), with a significant difference ( P < 0.001). A nonsignificant association ( P > 0.01) was observed with in-hospital mortality due to hypoxemia and body mass index. Conclusions: Our study supports the utility of S/F ratios in predicting specific clinical outcomes associated with COVID-19-induced ARDS.