Combining blood glucose and SpO 2 /FiO 2 ratio facilitates prediction of imminent ventilatory needs in emergency room COVID-19 patients

The increasing requirement of mechanical ventilation (MV) due to the novel coronavirus disease (COVID-19) is still a global threat. The aim of this study is to identify markers that can easily stratify the impending use of MV in the emergency room (ER). A total of 106 patients with COVID-19 requiring oxygen support were enrolled. Fifty-nine patients were provided MV 0.5 h (interquartile range: 0.3 to 1.4) post-admission. Clinical and laboratory data before intubation were collected. Using a multivariate logistic regression model, we identified four markers associated with the impending use of MV, including the ratio of peripheral blood oxygen saturation to fraction of inspired oxygen (SpO 2 /FiO 2 ratio), alanine aminotransferase, blood glucose (BG), and lymphocyte counts. Among these markers, SpO 2 /FiO 2 ratio and BG, which can be measured easily and immediately, showed higher accuracy (AUC: 0.88) than SpO 2 /FiO 2 ratio alone (AUC: 0.84), despite no significant difference (DeLong test: P = 0.591). Moreover, even in patients without severe respiratory failure (SpO 2 /FiO 2 ratio > 300), BG (> 138 mg/dL) was predictive of MV use. Measuring BG and SpO 2 /FiO 2 ratio may be a simple and versatile new strategy to accurately identify ER patients with COVID-19 at high risk for the imminent need of MV.