COVID-19 vs Non-COVID-19 ARDS: Comparing Characteristics, Outcomes

Although COVID-19 acute respiratory distress syndrome (ARDS) has some key differences from non-COVID-19 ARDS, these differences do not merit deviation from evidence-based ARDS management according to study results published in the Annals of the American Thoracic Society.

Researchers prospectively collected clinical demographics, and measured respiratory mechanical parameters and plasma interleukin levels from patients with COVID-19 ARDS. These endpoints were compared to a historical cohort of patients with viral ARDS, bacterial ARDS, and ARDS because of culture-negative pneumonia who were previously enrolled in the University of Pittsburg Acute Lung Injury Registry (ALIR) study before April 2020.

A total of 92 patients with ARDS were examined in the study; 27 patients with COVID-19 ARDS and 65 historical control individuals. Among the historical control individuals, 14 patients had viral ARDS, 21 patients had bacterial ARDS, and 30 patients had culture-negative ARDS (ie, clinically suspected pneumonia with negative microbiologic work-up). When differences between COVID-19 ARDS and historical ARDS were examined, patients with COVID-19 ARDS had higher body mass index and were more likely to be Black or residents of skilled nursing facilities compared with historical control individuals.

Although there were no differences in positive end-expiratory pressures (PEEP) between patients with COVID-19 and non-COVID-19 ARDS, patients with COVID-19 received lower minute ventilation compared with patients with bacterial ARDS and culture-negative ARDS. Additionally, COVID-19 patients had lower interleukin-6 (IL-6) levels compared with bacterial and culture-negative ARDS at early time points after intubation, but no differences in IL-6 levels compared with viral ARDS. Furthermore, patients with COVID-19 ARDS had longer duration of mechanical ventilation, but similar 60-day mortality.

“COVID-19 ARDS bears several similarities to viral ARDS but demonstrates lower minute ventilation and lower systemic levels of IL-6 compared to bacterial and culture-negative ARDS,” the study authors wrote. “Such detectable differences of COVID-19 do not merit deviation from evidence-based management of ARDS but suggest priorities for clinical research to better characterize and treat this new clinical entity.”

Reference

Bain W, Yang H, Shah FA, et al. COVID-19 versus non-COVID ARDS: comparison of demographics, physiologic parameters, inflammatory biomarkers and clinical outcomes. Ann Am Thorac Soc. Published online February 5, 2021. doi:10.1513/AnnalsATS.202008-1026OC