SILENT HYPOXIA IN COVID-19: IS IT MORE DANGEROUS? A RETROSPECTIVE COHORT STUDY

Abstract

TYPE: Late Breaking Abstract TOPIC: Critical Care PURPOSE: Silent hypoxia is the presence of hypoxia in absence of subjective experience of breathing discomfort. The aim of our study is to explore differences in disease outcomes in patients with silent hypoxia compared to patients with dyspneic hypoxia. METHODS: We retrospectively reviewed data of COVID-19 patients who were hypoxic at the time of presentation. Clinical, laboratory and treatment parameters were compared. Multivariate logistic regression models were fitted to identify the factors predicting mortality. RESULTS: Among 2080 patients with COVID-19 admitted to our hospital, 811 patients were hypoxic with SpO2<94% at the time of presentation. Out of 811 patients,174 (21.45%) did not have complaints of shortness of breath since the onset of COVID-19 symptoms. 5.2% of patients were completely asymptomatic for COVID-19 and were found to be hypoxic only on pulse oximetry. The case fatality rate in patients with silent hypoxia was 45.4% as compared to 40.03% in hypoxic patients admitted with complaints of dyspnea (P=0.202). The odds ratio of death was 1.1 (95% CI 0.41-2.97) in the patients with silent hypoxia after adjusting for baseline characteristics, laboratory parameters, treatment, and in-hospital complications, which did not reach statistical significance (P=0.851). CONCLUSIONS: Silent hypoxia may be the only presenting feature of COVID-19. Since the case fatality rate is comparable between silent and dyspneic hypoxia, it should be recognized early and treated as aggressively as dyspneic hypoxia for improving disease outcomes. CLINICAL IMPLICATIONS: Silent hypoxia and dyspneic hypoxia have similar outcomes, it is of paramount importance to do pulse oximetry in every patient diagnosed with SARS-CoV-2 infection. DISCLOSURE: Nothing to declare. KEYWORD: Silent Hypoxia