Negative Pleural Fluid Cultures among Patients with Pleural Effusion in a Tertiary Care Hospital: A Descriptive Cross-sectional Study

INTRODUCTION: A systematic approach to analysis of the fluid in conjunction with the clinical presentation allows clinicians to diagnose the cause of an effusion, narrow the differential diagnoses, and design a management plan. However, the number of cases where pleural fluid examination gives no proper diagnosis is depressingly high. This study aims to find out the prevalence of negative pleural fluid cultures among patients with pleural effusion in a tertiary care hospital. METHODS: This was a descriptive cross-sectional conducted among 273 patients with pleural effusion admitted to a tertiary care hospital between January, 2019 and February, 2020. Ethical clearance was taken from the Institutional Review Committee (Reference number: 134/20). Convenience sampling was done. All patients whose pleural fluid was sent for analysis during the study period were included in the study. Pleural fluid analysis was done, and data were analysed using Statistical Package for the Social Sciences 25.0. Point estimate was done at a 95% Confidence Interval along with frequency and percentages for binary data. RESULTS: Among 273 pleural fluid cultures from patients with pleural effusion, negative pleural fluid cultures were seen in 269 (98.53%) (97.12-99.96 at a 95% Confidence Interval). CONCLUSIONS: Our study reported that the prevalence of negative pleural fluid cultures was higher when compared to similar studies conducted in similar settings. The routine pleural fluid analysis could add a very little to the diagnosis and management of pleural effusion.