Abstract
Introduction. Pleural empyema is common but microbiological diagnosis is challenging, often leading to prolonged empiric broad-spectrum antimicrobial use.Hypothesis. 16S rRNA PCR on operative pleural tissue will increase diagnostic yield and improve antibiotic stewardship in patients with surgically managed pleural empyema.Aim. The objective was to characterize the clinical and microbiological characteristics of surgically managed pleural empyema, assess the diagnostic yield of 16S rRNA PCR and determine its impact on antimicrobial use.Methodology. This retrospective study identified patients with pleural empyema at a tertiary thoracic referral unit in North London, UK, between March 2019 and March 2023. Demographic, clinical and microbiological characteristics were collected.Results. One hundred eighty-three patients underwent surgery for pleural empyema at University College Hospital at Westmoreland Street over a 4-year period. Most empyemas were community-acquired, and the main surgical modality was minimally invasive video-assisted thoracoscopic surgery (151/183, 82.5%). Thirty-day all-cause post-operative mortality was 0.6%. Microbial aetiology was ascertained in 47%, with Streptococcus anginosus group, Streptococcus pneumoniae and anaerobes most frequently identified. Operative pleural tissue 16S rRNA PCR had a high diagnostic yield compared to conventional culture alone (68.2% vs. 26.4%). Post-operatively, antibiotics were prescribed for a median of 14 days (interquartile range 10-18), the majority broad spectrum (169/181, 93.4%). 16S PCR impacted antimicrobial prescribing in one-tenth of cases when used (4/32, 12.5%); however, turnaround times limited its impact.Conclusion. Molecular diagnostics improve bacterial detection and antibiotic stewardship in pleural empyema. Streamlining molecular diagnostics pathways or developing pleural-specific multiplex PCR panels could further enhance management.