Evaluating the presence of SARS-CoV-2 RNA in the pleural fluid of patients undergoing pleural procedures without symptoms of COVID-19

Abstract

Intro: The pandemic has put a strain on healthcare services and resources. Overall procedure capacity was reduced and cancer diagnostic pathways were disrupted. The procedural urgency associated with symptomatic patients with often undiagnosed malignant pleural effusion means that nasopharyngeal PCR testing to exclude COVID-19 prior to procedures can often be impractical or logistically challenging

Aim: To assess two hypotheses; that SARS-CoV-2 could not be detected in pleural fluid samples from patients with no clinical features of COVID-19 and that pleural procedures can be conducted safely using a pragmatic infection control strategy in the context of a respiratory pandemic

Methods: 24 patients completed a screening questionnaire covering symptoms, travel and contacts. If there was no clinical evidence of COVID-19 infection, the day case intervention could proceed as planned, otherwise a negative nasopharyngeal PCR swab within 48 hours was required. Pleural fluid specimens were prospectively collected for the Oxford Radciffe Biobank study and promptly processed and stored using pre-specified protocols. Viral RNA extraction was performed using the QIAamp UltraSens kit (Qiagen, Germany)

Result: All patients had no clinical evidence of COVID-19 infection and therefore none required nasopharyngeal PCR swabs. qPCR assays did not detect SARS-CoV-2 virus in pleural fluid of any of the patients.

Conclusion: In the absence of clinical evidence of COVID-19, SARS-CoV-2 is unlikely to be detected in pleural fluid. In the face of an ongoing pandemic, urgent outpatient pleural procedures can be safely continued, so as not to negatively impact the care for non-COVID patients