Safety and efficacy of antimicrobial optimization based on negative results from BioFire FilmArray Pneumonia panel and respiratory culture.

Background: The BioFire FilmArray Pneumonia (BFP) panel is a multiplexed nucleic acid test intended to detect respiratory pathogens from sputum or bronchoalveolar lavage (BAL) specimens. Efficacy and safety of de-escalation strategies in patients with negative BFP results remain unclear.

Methods: This was a multicenter, retrospective analysis of patients with suspected pneumonia and negative BFP and respiratory cultures. Patients were stratified into two groups: those whose antibiotic therapy was discontinued or withheld within 48 hours of a negative BFP (ATDW group) and those whose antibiotic therapy was continued (ATC group). We evaluated composite primary outcome of in-hospital mortality and 30-day readmission due to pneumonia (PNA) or recurrent PNA during index admission and secondary safety outcomes.

Results: Among 500 patients with negative BFP assay, a total of 185 patients were included in the final analysis (59 ATDW vs. 126 ATC). The ATDW group had significantly shorter total duration of antibiotic therapy (1 day vs 7 days, p < 0.001). The primary composite outcome was similar between ATDW and ATC groups (23.1% vs 35.3%, P = 0.15). Multivariate analysis identified ICU admission and/or intubation (OR 7.5, 95% CI 3.17-17.52, P < 0.001) as only independent predictor of the composite primary outcome. The ATDW group experienced fewer rates of acute kidney injury (AKI)(8% vs 37%, P = 0.004).

Conclusion: Antimicrobial optimization based on negative results from both BFP and respiratory culture may potentially reduce unnecessary antibiotic exposure and AKI in hospitalized patients with suspected pneumonia without increasing the risk of mortality and readmission.