Rapid testing with molecular syndromic panels of patients presenting at the emergency department with pneumonia at risk for multidrug-resistant pathogens

Background: Pneumonia remains a major cause of morbidity and mortality worldwide. Rapid diagnostic testing with molecular syndromic panels (MSP) has proved useful for the management of antimicrobial treatment of hospital-acquired pneumonia (HAP). In this study, we evaluated the impact of early use of MSP testing in the Emergency Department (ED) for the management of antibiotic therapy in patients with moderate to severe CAP with risk factors for multi-drug-resistant pathogens (CAP-MDR). Patients and methods: Patients presenting at the ED with diagnosis of moderate to severe CAP-MDR underwent microbiological analysis of lower respiratory tract specimens by culture and MSP testing (bioMérieux, FilmArray® Pneumonia Plus Panel). The primary outcome was the percentage of cases in which MSP testing modified the empiric antimicrobial therapy started according to local protocols. Among the secondary outcomes we included the time elapsed from ED admission to antibiotic change or confirmation upon receipt of the MSP results. Results: Between June 2024 and May 2025, 93 patients were enrolled (age, 72.9 ± 13.9 years; 62.4% males). MSP testing identified one or more pathogens in 91.4% of cases. Modification of empiric antibiotic therapy, started according to local protocols, occurred in 65.6% of patients (escalation in 44.1% and de-escalation in 21.5% of cases) after 11.4 ± 6.3 h (IQR 12.0) since ED presentation. Conclusions: The early use of MSP on lower respiratory samples collected in the ED from patients with diagnosis of moderate to severe CAP-MDR could allow a rapid and targeted modification of the empiric antibiotic therapy in these patients, with potential advantages on antimicrobial stewardship and patient management.