Pleural fluid characteristics of patients with COVID‐19 infection

Abstract

Abstract Introduction Pleural effusions are known to occur in many cases of COVID‐19. Data on typical characteristics of COVID‐19‐associated pleural effusions are limited. The goal of this project was to characterize the pleural fluid from patients with COVID‐19. Methods We retrospectively collected electronic medical record data from adults hospitalized at a large metropolitan hospital system with COVID‐19 infection who had a pleural effusion and a thoracentesis performed. We assessed pleural fluid characteristics and applied Light's criteria. Results We identified 128 effusions from 106 unique patients; 45.4% of the effusions had fluid/serum protein ratio greater than 0.5, 33.9% had fluid/serum lactate dehydrogenase (LDH) greater than 0.6, and 56.2% had fluid LDH greater than 2/3 of the serum upper limit of normal. Altogether, 68.5% of effusions met at least one of these three characteristics and therefore were exudative by Light's criteria. The white blood cell (WBC) differential was predominantly lymphocytic (mean 42.8%) or neutrophilic (mean 28.7%); monocytes (mean 12.7%) and eosinophils (mean 2.5%) were less common. Conclusion We demonstrate that 68.5% of pleural effusions in patients with COVID‐19 infection were exudative and hypothesize that COVID‐19‐associated pleural effusions are likely to be exudative with WBC differential more likely to be predominantly lymphocytic.

Keywords

• COVID‐19
• Light's criteria
• pleural effusion
• pneumonia
• SARS‐CoV‐2
• thoracentesis