Epidemiology and Clinical Patterns of Lung Abscesses in ICU

Background Data are scarce regarding epidemiology and management of critically ill patients with lung abscesses. Research question What are the clinical and microbiological characteristics of critically ill patients with lung abscesses, how are they managed in the ICUs, and what are the risk factors of in-ICU mortality? Study Design and Methods Retrospective observational multicenter study, based on ICD-10 codes, between 2015 and 2022 in France. In-ICU mortality-associated factors were determined by multivariate logistic regression. Results We analyzed 171 ICU patients with pulmonary abscesses. 78% were male with a mean age of 56.5 ± 16.4 years. 20.4% were excessive alcohol users, 25.2% had a chronic lung disease (14% COPD), and 20.5% had a history of cancer. Overall, 40.9% were immunocompromised and 38% qualified for nosocomial infection. Presenting symptoms included fatigue or weight loss in 62%, fever (50.3%) and dyspnea (47.4%). Hemoptysis was reported in 21.7%. A polymicrobial infection was present in 35.6%. The most frequent pathogens were Enterobacteriaceae in 31%, S. aureus in 22% and Pseudomonas aeruginosa in 19.3%. 10.5% were fungal infections. Several clusters of clinico-radiological patterns were associated with specific microbiological documentation and could guide empiric antibiotic regimen. 11.7% had percutaneous abscess drainage; surgery was performed in 12.7%, and 12% required bronchial-artery embolization for hemoptysis. In-ICU mortality was 21.5%, and age [OR: 1.05 (1.02-1.91), P=0.007], RRT during ICU stay [OR: 3.56 (1.24–10.57), P=0.019], and fungal infection [OR: 9.12 (2.69-34.5), P=0.0006] were independent predictors of mortality after multivariate logistic regression, while drainage or surgery were not. Interpretation Pulmonary abscesses in the ICU are a rare but severe disease often resulting from a polymicrobial infection with a high proportion of Enterobacteriaceae, S. aureus, and P. aeruginosa. Percutaneous drainage, surgery or arterial embolization was required in more than a third of cases. Further prospective studies focusing on first-line antimicrobial therapy and source control procedure are warranted to improve and standardize patient management.