Evaluating the Impact of Filmarray Pneumonia Plus Planel in Therapeutic Decision-Making in Critical Patients With Suspected Respiratory Infection

Background: Respiratory infections in critically ill patients remain a major challenge in intensive care units (ICUs), with high morbidity and mortality. Conventional microbiological methods often fail to identify the causative pathogen promptly, particularly in patients previously exposed to antibiotics. Multiplex molecular platforms, such as the BioFire FilmArray® Pneumonia Panel Plus (FAPP), allow rapid detection of multiple respiratory pathogens and resistance markers, potentially improving early therapeutic decision-making. Objectives: To evaluate the impact of implementing FAPP on antimicrobial therapeutic decisions in critically ill patients with suspected respiratory infection. Methods: We conducted a retrospective cohort study in two mixed ICUs between 2023 and 2024. All respiratory samples in which FAPP was requested were analyzed. Results were compared with conventional cultures, and changes in antimicrobial therapy following FAPP results were assessed, classified as escalation/initiation or de-escalation/discontinuation. Concordance between FAPP and culture was evaluated, and clinical and demographic variables were analyzed. Differences between groups were assessed using p-values obtained from the chi-square test or the Mann–Whitney test. Results: A total of 363 respiratory samples were included, 88.4% from mechanically ventilated patients. FAPP was positive in 65.3% of samples, whereas cultures were positive in 23.1%. Overall concordance between FAPP and culture was 57.3%. In 42.4% of cases, pathogens were detected exclusively by FAPP. Antimicrobial therapy was modified in 29.8% of patients, predominantly through de-escalation or discontinuation (69.4% of changes). Therapeutic modifications were more frequent in nosocomial infections and in patients with a positive FAPP result. Conclusions: The use of FAPP in critically ill patients with suspected respiratory infection provides rapid microbiological information that significantly influences antimicrobial decision-making, particularly by facilitating antibiotic de-escalation. Although discrepancies with conventional cultures remain and require careful clinical interpretation, FAPP represents a valuable tool for antimicrobial stewardship in the ICU setting.