The Association between Mortality and the Oxygen Saturation and Fraction of Inhaled Oxygen in Patients Requiring Oxygen Therapy due to COVID-19–Associated Pneumonia

Abstract

Background The coronavirus disease (COVID-19) can manifest in a range of symptoms, including both asymptomatic systems which appear nearly non-existent to the patient, all the way to the development of acute respiratory distress syndrome (ARDS). Specifically, COVID-19–associated pneumonia develops into ARDS due to the rapid progression of hypoxia, and although arterial blood gas analysis can assist in halting this deterioration, the current environment provided by the COVID-19 pandemic, which has led to an overall lack of medical resources or equipment, has made it difficult to administer such tests in a widespread manner. As a result, this study was conducted in order to determine whether the levels of oxygen saturation (SpO 2 ) and the fraction of inhaled oxygen (FiO 2 ) (SF ratio) can also serve as predictors of ARDS and the patient’s risk of mortality. Methods This was a retrospective cohort study conducted from February 2020 to Mary 2020, with the study’s subjects consisting of COVID-19 pneumonia patients who had reached a state of deterioration that required the use of oxygen therapy. Of the 100 COVID-19 pneumonia cases, we compared 59 pneumonia patients who required oxygen therapy, divided into ARDS and non-ARDS pneumonia patients who required oxygen, and then investigated the different factors which affected their mortality. Results At the time of admission, the ratios of SpO 2 , FiO 2 , and SF for the ARDS group differed significantly from those of the non-ARDS pneumonia support group who required oxygen (p<0.001). With respect to the predicting of the occurrence of ARDS, the SF ratio on admission and the SF ratio at exacerbation had an area under the curve which measured to be around 85.7% and 88.8% (p<0.001). Multivariate Cox regression analysis identified that the SF ratio at exacerbation (hazard ratio [HR], 0.916; 95% confidence interval [CI], 0.846–0.991; p=0.029) and National Early Warning Score (NEWS) (HR, 1.277; 95% CI, 1.010–1.615; p=0.041) were significant predictors of mortality. Conclusion The SF ratio on admission and the SF ratio at exacerbation were strong predictors of the occurrence of ARDS, and the SF ratio at exacerbation and NEWS held a significant effect on mortality.

Prognostication using SpO2/FiO2 in invasively ventilated ICU patients with ARDS due to COVID-19 – Insights from the PRoVENT-COVID study

“…However, this study did not report on arterial blood gas and ventilation data, and 28-day mortality was 94.7% in patients receiving respiratory support, which is substantially higher than other reports on outcome [ 2 , 14 ]. Another retrospective analysis evaluated SpO 2 /FiO 2 for the prediction of mortality and the occurrence of ARDS, and found a similar cutoff value of 179 as this current study [ 32 ]. However, the sample size was limited, arterial blood gas analysis was frequently unavailable, and FiO 2 could not be accurately measured in patients with non-invasive oxygen delivery methods.…”

Adult patients admitted to a tertiary hospital for COVID-19 and risk factors associated with severity: a retrospective cohort study

“…The PaO 2 of the ABG, even with hypoxemia, did not prove to be a significant factor for severity. In the study by Choi et al 32 , the SpO 2 /FiO 2 ratio upon admission presented an area under the receiver operating characteristic curve (ROC) around 85.7%, characterizing the SpO 2 /FiO 2 ratio as a strong predictor for the occurrence of ARDS. The WHO 33 recommended the SpO 2 /FiO 2 ratio when PaO2 is not available, considering values ≤ 315 as suggestive of SARS, including non-ventilated patients.…”

The Effectiveness of the Use of Regdanvimab (CT-P59) in Addition to Remdesivir in Patients with Severe COVID-19: A Single Center Retrospective Study

“…When the patient wore a simple oxygen mask, the FiO 2 value was calculated to be 0.4 for 5–6 L/min. A FiO 2 value of 0.8 was calculated if the patient was receiving oxygen > 10 L/min with a mask with a reservoir bag [ 18 ]. CXR scoring was performed by two thoracic radiologists (W. J. Kwon and S. Lim), with two CXRs at the time around remdesivir start and hospital discharge using the method described in a recent paper [ 17 ].…”