PLEURAL FLUID AGITATION FOR IMPROVING THE MICROBIOLOGIC DIAGNOSTIC YIELD IN PLEURAL INFECTION – A FEASIBILITY STUDY

The lack of a defined microbial etiology in at least 40% of patients with pleural infection means empirical broader spectrum antibiotics for a longer duration with associated patient risks, burden and increased costs. Findings from the AUDIO study suggested that bacteria are mainly concentrated on pleural surface rather than being planktonic in pleural fluid.<bold>Aim</bold>:To investigate whether pleural fluid agitation prior to sample aspiration can improve the diagnostic microbiologic yield.<bold>Methods:</bold> A comparative feasibility study recruited 30 patients with non-tuberculous infected pleural effusion at a tertiary care hospital. US-guided thoracentesis was performed with initial standard aspiration sampling technique, followed by pleural fluid agitation into the pleural cavity for 3-5 cycles before collection. Samples were cultured in aerobic and anaerobic media.<bold>Results:</bold> <table-wrap><object-id>erj;64/suppl_68/PA1498/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col></colgroup><tbody><tr><td></td><td>n=30</td></tr><tr><td>Age, years</td><td>50.4(16.7)</td></tr><tr><td>Males, n (%)</td><td>24 (80%)</td></tr><tr><td>BMI, Kg.m2</td><td>25.8 (4.9)</td></tr><tr><td>Ever smokers</td><td>22 (73.3%)</td></tr><tr><td>RAPID score</td><td>2.7 (1.6)</td></tr><tr><td>≥1 Comorbidity</td><td>27 (90%)</td></tr><tr><td><italic>Pleural fluid</italic></td><td></td></tr><tr><td>Glucose (mg/dL)</td><td>68.4 (98.6)</td></tr><tr><td>Protein (g/dL)</td><td>4.5 (2.2)</td></tr><tr><td>LDH (U/L)</td><td>7099 (8999)</td></tr><tr><td>WBC count (cells/µL)</td><td>5131 (5733)</td></tr></tbody></table></table-wrap> No complications encountered with the agitation technique. 14 (46.6%) patients had a positive pleural fluid culture result. No yield discordance noted between both sampling techniques except for 1 extra agitated sample growing klebsiella & another agitated sample showing additional anerobic growth. Four (28.5%) of 14 positive samples showed higher colony count in the agitated samples by semi-quantitative scoring methods.<bold>Conclusion</bold>:No overall difference was noted between both techniques, however agitated samples grew higher colony count in >25% of the positive samples suggesting a possible signal for further investigation in a larger adequately powered study.