Silent hypoxia in patients with SARS CoV-2 infection before hospital discharge

• Published in: International journal of infectious diseases Vol. 99; pp. 100 - 101
• Main Authors: Fuglebjerg, Natascha Josephine Ulstrand, Jensen, Tomas Oestergaard, Hoyer, Nils, Ryrsø, Camilla Koch, Lindegaard, Birgitte, Harboe, Zitta Barrella
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.10.2020; The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases; Elsevier
• Subjects: Betacoronavirus; Coronavirus Infections - complications; COVID-19; Discharge; Dyspnea; Exercise Test; Humans; Hypoxia; Hypoxia - diagnosis; Hypoxia - etiology; Pandemics; Patient Discharge; Pneumonia, Viral - complications; SARS-CoV-2; Short Communication; COVID-19; Hypoxia; Dyspnea; Exercise test; Discharge
• ISSN: 1201-9712; 1878-3511; 1878-3511
• DOI: 10.1016/j.ijid.2020.07.014

•Anecdotal reports of asymptomatic ‘silent hypoxia’ in COVID-19 are emerging•A minimal increase in dyspnea was seen with worsening hypoxia during exercise•The 6-minute walking test is a potential tool in discharge assessment To assess the degree of hypoxia and subjective dyspnea elicited by a 6-minute walking test (6MWT) in COVID-19 patients prior to discharge. A 6MWT was performed in 26 discharge-ready COVID-19 patients without chronic pulmonary disease or cardiac failure. Heart rate, oxyhemoglobin saturation (SpO2), respiratory rate, and subjective dyspnea measured on the Borg CR-10 scale were measured before and immediately after the 6MWT, with continuous monitoring of SpO2 and heart rate during the 6MWT. The 6MWT was terminated if SpO2 dropped below 90%. A historical cohort of 204 patients with idiopathic pulmonary fibrosis (IPF) was used for comparison. 13 (50%) of the COVID-19 patients developed exercise-induced hypoxia (SpO2 < 90%) during the 6MWT, of which one third had pulmonary embolism. COVID-19 patients experienced less hypoxia-related dyspnea during the 6MWT compared with patients with IPF. The 6MWT is a potential tool in the diagnosis of asymptomatic exercise-induced hypoxia in hospitalized COVID-19 patients prior to discharge. Due to important methodological limitations, further studies are needed to confirm our findings and to investigate their clinical consequences.