Pleural abnormalities in COVID-19: a narrative review

Abstract

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.

Keywords: COVID-19; pleura; pleural effusion; pneumothorax; radiology.

Figure 1

Axial chest imaging with pleural changes often seen in early disease. (A) CT chest in a 70-year old male obtained 5 days following hospitalization showed pleural thickening (blue arrow) adjacent to subpleural parenchymal infiltrate. (B) CT scan of the chest in a 55-year old male seven days after admission demonstrated bilateral pleural retraction (red arrow).

Figure 2

Pleural involvement in progressive late disease. (A) Axial CT scan of the chest four weeks following hospitalization in a 60-year old man without any comorbidities revealed a small right sided pleural effusion. Advanced fibrotic changes with traction bronchiectasis was present bilaterally. Parenchymal destruction with pneumatocele formation was noted in the anterior right chest. (B) CT scan of the chest in a 51-year old male 30 days after hospitalization demonstrated bilateral pneumatocele formation. The patient developed a left sided pneumothorax and underwent small bore chest tube placement. Advanced pulmonary parenchymal changes were also seen.