Trends in the Incidence, Etiology, Treatment, and Outcomes of Pleural Infections in Adults Over a Decade in a Finnish University Hospital

Background and Aims: The aim of the study was to ascertain changes in the incidence, etiology, treatment, and outcomes of pleural infections over a decade in a Finnish University Hospital. Materials and Methods: All patients treated for pleural infections in Tampere University Hospital during 2000-2008 and 2012-2016 were included. The incidence rates and the epidemiologic data and medical history of patients, etiology of infection, and treatment trends and outcomes were compared between the cohorts. Results: The incidence of pleural infections increased from 4.4 during 2000-2008 to 9.9 during 2012-2016 per 100.000 patient-years, p < 0.001. The patients in the latter group were older, 63 versus 57 years, p = 0.001, and the prevalence of chronic lung disease, hypertension, heart failure, dyslipidemia, and immunosuppressive medication were higher. The causes of infection remained similar and pneumonia accounted for 70% of all cases. The identification rate of the microbe pathogens increased from 49% to 64%, p = 0.002, while the distribution of identified pathogens was unchanged. More patients in the latter cohort were treated operatively, 88.3% versus 80.9%, p = 0.005, and, in these, the proportion of thoracoscopic surgery was higher, 57.4% versus 8.0%, p < 0.001, and the delay to surgery shorter, 5 versus 7 days, p < 0.001. Radiologic outcomes were similar. The 30-day mortality rate was 3.1% during 2000-2008 and 5.1% during 2012-2016, p = 0.293. conclusion: The overall incidence of pleural infections has increased significantly while the causes of pleural infections and the distribution of pathogens remain unchanged. Contemporary patients are older with higher prevalence of comorbidities and more frequently undergo thoracoscopic surgery.