Initial oxygen saturation at presentation as a predictor of mortality in COVID-19-positive cases in a tertiary care center in South India

Background: The rapid emergence of novel coronavirus 2019 (COVID-19) infections has resulted in infection to millions of people and hundreds of deaths around the world. India is ranking second in terms of the number of COVID-19 cases. Although there is no specific treatment for COVID, early recognition and supportive treatment can help in reducing mortality. Aims: The aim of this study is to describe the association between the initial oxygen saturation when the patient presented to the hospital and the risk of mortality. Methods: This is a retrospective study of all laboratory-confirmed cases of COVID-19 patients admitted in Government Hospital for Chest and Communicable Diseases (GHCCD), tertiary hospital in Visakhapatnam from April to June month of 2021. Demographic, clinical history, initial oxygen saturation, comorbidities, and outcome data were collected from GHCCD and were entered in MS Excel. The data were analyzed using univariate binomial logistic regression and generalized linear model with Poisson distribution. Results: By using multiple Cox regression, oxygen saturation values of less than 90% on admission correlated with mortality, presenting 1.67 (95% confidence interval [CI] 1.02–3.36), 2.23 (95% CI 1.89–5.63), 4.89 (95% CI 3.02–8.09), 6.97 (95% CI 4.63–11.07), and 9.87 (95% CI 5.23–13.53) times greater risk of death for SPO2 of 89–80, 79–70, 69–60, 59–50, and 49–40, respectively, when compared to patients with SPO2 >90%. We included 306 COVID-19-positive patients with a median age of 46 years. Of these, 64.05% were males and 36.94% were females. Risk associated with worse outcome included males, old age, comorbidities like hypertension (47.38%), diabetes (37.58%), cardiac disease (4.9%), hypothyroidism (3.26%), Chronic kidney disease (CKD) (3.26%), and malignancies (1.63%). Conclusions: SPO2 below 90% on admission is a strong predictor of mortality in patients with COVID-19. Risk factors for poor outcomes among COVID-19 cases include old age, males, diabetic patients, hypertensive patients, cardiac patients, and chronic kidney disease patients.