Clinical and Biologic Profiles of Patients with Acute Respiratory Distress Syndrome by Prevalence of Chronic Obstructive Pulmonary Disease or Emphysema; A Cohort Study

Abstract Introduction: Acute respiratory distress syndrome (ARDS) is a critical care disorder characterized by diffuse lung injury. The impact of pre-existing chronic obstructive pulmonary disease (COPD) or emphysema on ARDS pathogenesis is not well characterized. Methods: Secondary analysis of ARDS patients enrolled in the Acute Lung Injury Registry and Biospecimen Repository at the University of Pittsburgh between June 2012 and September 2021. Patients were categorized into two mutually exclusive groups by the prevalence of COPD or emphysema at the time of ARDS diagnosis. The COPD/emphysema group comprised ARDS patients with radiological evidence of emphysema, chart diagnosis of COPD, or both. Demographics, lung mechanics, and clinical outcomes were obtained from the electronic medical record. Host-response biomarkers known to have validated associations with ARDS were previously measured in plasma and lower respiratory tract samples using a customized Luminex assay. Continuous and categorical variables were compared between groups with and without COPD/emphysema. Results: 217 patients with ARDS were included in the study, 57 (27%) had COPD/emphysema. Patients with COPD/emphysema were older (median 62 interquartile range 55-69 versus 53 41-64 years, pConclusion: ARDS patients with COPD or emphysema had similar respiratory mechanics, host response biomarker profiles, and mortality compared to those without COPD or emphysema but with a shorter median duration of mechanical ventilation and ICU length of stay. Future studies should address differences in clinical and biological responses by disease severity, and should investigate the impact of severity of COPD and emphysema on mechanical ventilation and targeted therapeutic strategies in ARDS.