Pleural Effusion in COVID-19 Pneumonia: Clinical and Prognostic Implications-An Observational, Retrospective Study

Sara Cappelli; Elisabetta Casto; Marta Lomi; Alessandra Pagano; Luciano Gabbrielli; Roberta Pancani; Ferruccio Aquilini; Giulia Gemignani; Laura Carrozzi; Alessandro Celi

doi:10.3390/jcm12031049

Pleural Effusion in COVID-19 Pneumonia: Clinical and Prognostic Implications-An Observational, Retrospective Study

J Clin Med. 2023 Jan 29;12(3):1049. doi: 10.3390/jcm12031049.

Authors

Sara Cappelli^{1

2}, Elisabetta Casto^{1

2}, Marta Lomi^{1

2}, Alessandra Pagano^{1

2}, Luciano Gabbrielli², Roberta Pancani², Ferruccio Aquilini³, Giulia Gemignani³, Laura Carrozzi^{1

2}, Alessandro Celi^{1

2}

Affiliations

¹ Department of Surgical, Medical and Molecular Pathology and Critical Care, University of Pisa, 56126 Pisa, Italy.
² Pneumology Unit, Pisa University Hospital, 56126 Pisa, Italy.
³ OU Organization of Hospital Services, Pisa University Hospital, 56126 Pisa, Italy.

Abstract

Background: COVID-19 presents with a wide spectrum of clinical and radiological manifestations, including pleural effusion. The prevalence and prognostic impact of pleural effusion are still not entirely clear.

Patients and methods: This is a retrospective, single-center study including a population of consecutive patients admitted to the University Hospital of Cisanello (Pisa) from March 2020 to January 2021 with a positive SARS-CoV-2 nasopharyngeal swab and SARS-CoV-2-related pneumonia. The patients were divided into two populations based on the presence (n = 150) or absence (n = 515) of pleural effusion on chest CT scan, excluding patients with pre-existing pleural effusion. We collected laboratory data (hemoglobin, leukocytes, platelets, C-reactive protein, procalcitonin), worst PaO₂/FiO₂ ratio as an index of respiratory gas exchange impairment, the extent of interstitial involvement related to SARS-CoV-2 pneumonia and data on intensity of care, length of stay and outcome (discharge or death).

Results: The prevalence of pleural effusion was 23%. Patients with pleural effusion showed worse gas exchange (p < 0.001), longer average hospital stay (p < 0.001), need for more health care resources (p < 0.001) and higher mortality (p < 0.001) compared to patients without pleural effusion. By multivariate analysis, pleural effusion was found to be an independent negative prognostic factor compared with other variables such as increased C-reactive protein, greater extent of pneumonia and older age. Pleural effusion was present at the first CT scan in most patients (68%).

Conclusions: Pleural effusion associated with SARS-CoV-2 pneumonia is a relatively frequent finding that is confirmed to be a negative prognostic factor. Identifying early prognostic factors in an endemic-prone disease such as COVID-19 is necessary to optimize its clinical management. Further clinical studies aimed at better characterizing pleural effusion in these patients will be appropriate in order to clarify its pathogenetic role.

Keywords: COVID-19; computer tomography; intensity of care; length of hospitalization; mortality; pleural effusion; prognosis; total severity score.

Grants and funding

This research received no external funding.