AbstractBackground and objective:
Current guidelines recommend empirical treatment againstPseudomonas aeruginosain community-acquired pneumonia (CAP) patients with specific risk factors. However, evidence to support these recommendations is limited. We evaluate the risk factors and the impact of antimicrobial therapy in patients hospitalized with CAP due toP. aeruginosa.Methods:
We performed a retrospective population-based study of >150 hospitals. Patients were included if they had a diagnosis of CAP andP. aeruginosawas identified as the causative pathogen. Univariate and multivariate analyses were performed using the presence of risk factors and 30-day mortality as the dependent measures.Results:
Seven hundred eighty-one patients withP. aeruginosapneumonia were identified in a cohort of 62 689 patients with pneumonia (1.1%). Of these, 402 patients (0.6%) were included in the study and 379 (0.5%) were excluded due to health care-associated pneumonia or immunosuppression. In patients with CAP due toP. aeruginosa, 272 (67.8%) had no documented risk factors. These patients had higher rates of dementia and cerebrovascular disease. Empirical antibiotic therapy againstP. aeruginosawithin the first 48 h of presentation was independently associated with lower 30-day mortality in patients with CAP due toP. aeruginosa(hazard ratio (HR) 0.42, 95% confidence interval (CI): 0.23–0.76) and in patients without risk factors forP. aeruginosaCAP (HR 0.40, 95% CI: 0.21–0.76).Conclusions:
Risk factor recommended by current guidelines only detect one third of the patients admitted with CAP due toP. aeruginosa. Risk factors did not define the whole benefit observed due to empirical therapy coveringP. aeruginosa.