Novel Pseudomonas aeruginosa scoring system to guide empiric anti-pseudomonal therapy in COPD patients with community-acquired pneumònia

Background: COPD is associated with the development of Community-Acquired Pneumonia (CAP). Limited data are available regarding the association of P. aeruginosa (PA) risk factors as predictors of appropriate selection of anti-PA antibiotics. Our aim was to developed a novel PA scoring system based on risk factors to guide appropriate selection of empiric anti-PA antibiotics in hospitalized COPD patients with CAP. Methods: This pre-planned analysis of an international, multicenter, point-prevalence study included immunocompetent COPD patients hospitalized with CAP. We developed a scoring system of independently associated risk factors for PA-CAP. The primary outcomes were prevalence of PA-CAP and the appropriate selection of empiric anti-PA antibiotics. Results: We enrolled 689 hospitalized COPD patients with CAP, with a prevalence of PA-CAP of 7% (n=45). The variables independently associated with PA-CAP were a previous PA infection or colonization (OR 14.2 [95%CI 5.7-35.2] – 3 points), hospitalization in the past 12 months (OR 3.7 [1.5-9.2] – 1 point), and the presence of bronchiectasis (OR 3.2 [1.4-7.2] - 1 point). The PA score-COPD (PAS-COPD) was stratified in 0, 1, 2, or ≥3 points with a PA-CAP prevalence of 2%, 5%, 20% and 50%, respectively. Current anti-PA empiric antibiotics overuse occurs in 54% of the patients, but after the application of the PAS-COPD the overuse of anti-PA empiric antibiotics may ideally drop to 6%. Conclusions: We developed a novel PAS-COPD that accurately identified the risk of PA-CAP and is able to assist providers in the appropriate use of anti-PA antibiotics in COPD patients hospitalized with CAP.