Characterising Empyemas at a UK tertiary centre

<bold>Background:</bold> Pleural effusions are diagnosed in about 200,000 patients per year in the UK. Of the causes, empyema’s are a significant cause with a mortality rate of 15%. Pleural procedures are key to diagnosing these. <bold>Methods:</bold> We completed a service evaluation looking at the pleural procedures carried out by the interventional radiology department as well as the respiratory department within the period of Nov 2023-April 2024. We looked at the demographics on patients with confirmed empyemas or those treated as empyemas. We focused on the samples collected, and the tests requested. Culture results were noted as well as the antimicrobial and clinical management of these patients. <bold>Results:</bold> Of the 98 pleural procedures completed between the two departments within this time frame, 13/98(13.3%) were confirmed as true Empyemas. Patients were aged between 22-86 years of which 62% were Males & 38% were females.6/13 (46.1%) of diagnosed Empyemas had a positive micro culture result which strongly influenced antimicrobial therapy. Most commonly found organisms were oral streptococcal species- Strep. intermedius(50%) and Strep. mitis (16.7%), in keeping with findings from similar studies done in Europe. We noted in particular that the presence of clear fluid visualised during the pleural procedure strongly correlated to negative cultures. In addition, 46.2% (6/13) of samples were sent in blood culture bottles appropriately increasing microbial yield. <bold>Conclusion:</bold> Lack of local guidelines on Empyema treatment resulted in the use of a wide variety of antibiotics prior to cultures results, however following culture results ,& liaising with appropriate infection/microbiology teams , assessing response to treatment helped direct treatment.