Characteristics of Pleural Effusion in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pneumonia

Pleural fluid characteristics of patients with COVID-19 infection

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.

COVID-19-Related Pleural Diseases

Coronavirus disease 2019 (COVID-19)-related pleural diseases are now well recognized. Since the beginning of the pandemic, increasing cases of pleural diseases including pneumothorax, pneumomediastinum, and pleural effusion with severe COVID-19 infection have attracted the attention of physicians and are not incidental or due to barotrauma. The complicated course of COVID-19 illness highlights the complex pathophysiological underpinnings of pleural complications. The management of patients with pneumothorax and pneumomediastinum is challenging as the majority require assisted ventilation; physicians therefore appear to have a low threshold to intervene. Conversely, pleural effusion cases, although sharing some similar patient characteristics with pneumothorax and pneumomediastinum, are in general managed more conservatively. The evidence suggests that patients with COVID-19-related pleural diseases, either due to air leak or effusion, have more severe disease with a worse prognosis. This implies that prompt recognition of these complications and targeted management are key to improve outcomes.

Effusion fluid cytology and COVID‐19 infection

Background

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which is responsible for coronavirus disease 2019 (COVID‐19), is known to cause severe respiratory infections with occasional accompanying pleural effusion (PE), pericardial effusion (PCE), or peritoneal effusion (PTE). The effect of COVID‐19 on effusion cytology is not yet known. This study aimed to examine the cytomorphologic features and workup of effusion fluids in patients with active COVID‐19 infection versus those in recovery.

Methods

PE (n = 15), PCE (n = 1), and PTE samples (n = 20) from hospitalized patients with a SARS‐CoV‐2 infection (from June 1, 2020, to December 30, 2020) were reviewed. Effusion fluids with metastatic carcinoma were excluded. Differential cell counts, cytomorphology, and relevant immunostains for effusion fluids were retrospectively evaluated and compared between patients with active infection (positive on a SARS‐CoV‐2 nucleic acid amplification test [NAAT] within 2 months; n = 23) and those in the recovery phase from COVID‐19 (negative on a SARS‐CoV‐2 NAAT for >2 months; n = 13).

Results

The cytology diagnoses were negative for malignancy (n = 31), atypical (n = 4), and suspicious for malignancy (n = 1). Active infection cases showed more atypical mesothelial cells than recovery cases (P < .05); some had enlarged nuclei, prominent nucleoli, occasional multinucleation, and bizarre nuclei. Immunostains were performed more often in active infection cases than recovery cases (47.8% vs 7.7%; P < .05). Differential cell counts (available for 28 cases) showed no significant differences between the active infection and recovery groups.

Conclusions

This study found atypical and bizarre mesothelial cells more often in effusions of cases with active COVID‐19 infection in comparison with patients in recovery. It is important for cytopathologists to become familiar with the cytomorphologic effects of SARS‐CoV‐2 on effusion cytology so that these cases can be properly triaged.

This study examined the cytomorphologic features and work‐up of effusion fluids in patients with active COVID‐19 infection versus those in recovery, and found atypical and bizarre mesothelial cells to be present more often in effusions of cases with active COVID‐19 infection than those from patients in recovery. It is important for cytopathologists to become familiar with the cytomorphologic effects of SARS‐CoV‐2 on effusion cytology.

Pleural abnormalities in COVID-19: a narrative review

Objective

This narrative review aims to provide a detailed overview of pleural abnormalities in patients with coronavirus disease 19 or COVID-19.

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is a novel beta coronavirus responsible for COVID-19. Although pulmonary parenchymal and vascular changes associated with COVID-19 are well established, pleural space abnormalities have not been the primary focus of investigations.

Methods

Narrative overview of the medical literature regarding pleural space abnormalities in COVID-19. The appropriate manuscripts were identified by searching electronic medical databases and by hand searching the bibliography of the identified papers. Pleural abnormalities on transverse and ultrasound imaging are discussed. The incidence, clinical features, pathophysiology, and fluid characteristics of pleural effusion are reviewed. Studies reporting pneumothorax and pneumomediastinum are examined to evaluate for pathogenesis and prognosis. A brief comparative analysis of pleural abnormalities among patients with COVID-19, severe acute respiratory syndrome (SARS), and Middle Eastern respiratory syndrome (MERS) has been provided.

Conclusions

Radiologic pleural abnormalities are common in COVID-19, but the incidence of pleural effusion appears to be low. Pneumothorax is rare and does not independently predispose the patient to worse outcomes. SARS-CoV-2 infects the pleural space; however, whether the pleural fluid can propagate the infection is unclear.

The incidence of pleural effusion in COVID-19 pneumonia: State-of-the-art review

BACKGROUND

COVID-19-related pleural effusions are frequently described during the ongoing pandemic.

OBJECTIVES

We described the incidence, characteristics, and outcomes of COVID-19-related pleural effusions based on the current evidence available in the literature.

METHODS

We searched MEDLINE, Pubmed, and Google Scholar databases using keywords of "coronavirus disease 2019 (COVID-19)," "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)," "pleural effusion," "pleural fluid," and "pleura" from January 1st, 2020 to January 31st, 2021.

RESULTS

The incidence of pleural effusions was low at 7.3% among the 47 observational studies. Pleural effusions were commonly observed in critically ill patients and had Multisystem Inflammatory Syndrome (MIS). COVID-19-related pleural effusions were identified 5-7 days and 11 days, after hospital admission and onset of COVD-19 symptoms. The characteristic findings of pleural fluid were exudative, lymphocytic or neutrophilic-predominant pleural fluid with markedly elevated lactate dehydrogenase (LDH) levels and pleural fluid to serum LDH ratio.

CONCLUSION

A well-designed study is required to assess the significance of COVID-19-related pleural effusions during this current pandemic.

Pleural effusion in a patient with COVID-19 pneumonia and lung cancer: A case report

Coronavirus disease is a global infection presenting with a variety of clinical features, both pulmonary and extrapulmonary symptoms. Its diagnosis depend on clinical symptoms, laboratory tests, and the typical CT chest scan findings. In this report, a 72-year-old patient (known to have lung cancer) present with pleural effusion as possible sequel of COVID-19 pneumonia. Pleural effusion may present as a complication in a patient with coronavirus disease, but there is poor evidence to this claim in the medical literature.

Pleural effusion as an isolated finding in COVID-19 infection

Common radiological findings of COVID -19 infection include bilateral ground-glass opacities in lower lobes with a peripheral distribution. Pleural effusion is considered a rare manifestation of COVID -19 infection. We present a 52 years old patient with a three-week history of right-sided pleuritic chest pain, fever, and dyspnea. Laboratory investigations revealed high C-reactive protein and ferritin levels and a positive COVID-polymerase chain reaction (PCR) from a nasopharyngeal swab. Chest X-ray and Computed tomography (CT) identified a moderate right-sided pleural effusion, which was exudative with mixed cellularity and high Lactate dehydrogenase (LDH). Histopathology of thoracoscopic pleural biopsy didn't reveal granulomas, malignancy, or any microbiological growth. We postulate that having ruled out any other cause the effusion was likely related to the Covid-19 infection. Our case highlights that COVID-19 can present with isolated pleural effusions, therefore it should be kept as an etiology of effusions especially if other possible causes have been ruled out.