Silent hypoxia is not an identifiable characteristic in patients with COVID-19 infection

Plummer, Nicholas Russell; Fogarty, Andrew; Shaw, Dominick; Card, Timothy; West, Joe; Crooks, Colin

Abstract

Background: We aimed to assess whether asymptomatic (“happy”) hypoxia was an identifiable physiological phenotype of COVID-19 acute respiratory distress syndrome (ARDS), and associated with need for ICU admission. Methods: We performed an observational cohort study of all adult patients admitted with hypoxaemic respiratory failure to a large acute hospital Trust serving the East Midlands, UK. Patients with confirmed COVID-19 were compared to those without. Physiological response to hypoxaemia was modelled using a linear mixed effects model. Results: Of 1,586 patients included, 75% tested positive for SARS-CoV-2. The ROX index was 2.08 min−1 lower (1.56–2.61, p < 0.001) in the COVID-19 cohort when adjusted for age and ethnicity, suggesting an enhanced respiratory response to hypoxia compared to the non-Covid-19 patients. There was substantial residual inter- and intra-patient variability in the respiratory response to hypoxaemia. 33% of the infected cohort required ICU, and of these 31% died within 60 days. ICU admission and mortality were both associated with an enhanced respiratory response for all degrees of hypoxaemia. Conclusions: Patients with COVID-19 display a more symptomatic phenotype in response to hypoxaemia than those with other causes of hypoxaemic respiratory failure, however individual patients exhibit a wide range of responses. As such although asymptomatic hypoxaemia may be a phenomenon in any individual patient with hypoxaemic respiratory failure, it is no more frequently observed in those with SARS-CoV-2 infection than without.

Citation

Plummer, N. R., Fogarty, A., Shaw, D., Card, T., West, J., & Crooks, C. (2022). Silent hypoxia is not an identifiable characteristic in patients with COVID-19 infection. Respiratory Medicine, 197, Article 106858. https://doi.org/10.1016/j.rmed.2022.106858

• Journal Article Type: Article
• Acceptance Date: Apr 20, 2022
• Online Publication Date: Apr 24, 2022
• Publication Date: Jun 1, 2022
• Deposit Date: Apr 29, 2022
• Publicly Available Date: Apr 25, 2023
• Journal: Respiratory Medicine
• Print ISSN: 0954-6111
• Electronic ISSN: 1532-3064
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 197
• Article Number: 106858
• DOI: https://doi.org/10.1016/j.rmed.2022.106858
• Keywords: Pulmonary and Respiratory Medicine
• Public URL: https://nottingham-repository.worktribe.com/output/7838713
• Publisher URL: https://www.resmedjournal.com/article/S0954-6111(22)00123-8/fulltext