Emergency Department SpO2/FiO2 Ratios Correlate with Mechanical Ventilation and Intensive Care Unit Requirements in COVID-19 Patients

Abstract

Background: Patients with coronavirus 2019 (COVID-19) are at high risk for respiratory dysfunction. The pulse oximetry/fraction of inspired oxygen (SpO2/FiO2) ratio is a non-invasive assessment of respiratory dysfunction substituted for the PaO2:FiO2 ratio in Sequential Organ Failure Assessment scoring. We hypothesized that emergency department (ED) SpO2/FiO2 ratios correlate with requirement for mechanical ventilation in COVID-19 patients. Our objective was to identify COVID-19 patients at greatest risk of requiring mechanical ventilation, using SpO2/FiO2 ratios. Methods: We performed a retrospective review of patients admitted with COVID-19 at two hospitals. Highest and lowest SpO2/FiO2 ratios (percent saturation/fraction of inspired O2) were calculated on admission. We performed chi-square, univariate, and multiple regression analysis to evaluate the relationship of admission SpO2/FiO2 ratios with requirement for mechanical ventilation and intensive care unit (ICU) care. Results: A total of 539 patients (46% female; 84% White), with a mean age 67.6 ± 18.6 years, met inclusion criteria. Patients who required mechanical ventilation during their hospital stay were statistically younger in age (P = 0.001), had a higher body mass index (P 300 and mechanical ventilation or intensive care unit (ICU) requirement. Conclusion: The ED SpO2/FiO2 ratios correlated with mechanical ventilation and ICU requirements during hospitalization for COVID-19. These results support ED SpO2/FiO2 as a possible triage tool and predictor of hospital resource requirements for patients admitted with COVID-19. Further investigation is warranted.