Assessing FilmArray Pneumonia+ Panel dynamics during antibiotic treatment to predict clinical success in ICU patients with ventilated hospital-acquired pneumonia and ventilator-associated pneumonia: a multicenter prospective study

Background Accurate microbiological documentation seems central for managing severe pneumonia. While the FilmArray® Pneumonia + panel (FA-PP) offers rapid pathogen identification, its effectiveness during antibiotic treatment and in predicting clinical outcomes remains unclear. Methods We conducted a prospective observational study across four ICUs from April 2022 to June 2024, including patients with ventilator-associated pneumonia (VAP) or ventilated hospital-acquired pneumonia (vHAP). Bacterial loads were monitored on days 0, 1, 3, 7 and 10 and 3 days after stopping antibiotics, using endotracheal aspirates (ETAs) analyzed by FA-PP and standard cultures. The main objective was to assess the correlation between quantitative changes in FA-PP results and clinical success. Quantitative changes over time were analyzed using mixed ordinal logistic regression. Results Of the 93 patients enrolled, 60.2% (n = 56) achieved clinical success, while the ICU mortality rate was 25.8% (n = 24). Although FA-PP and culture quantification results declined over time (p < 0.0001), neither method consistently correlated with clinical success (non-significant for both). At diagnosis, FA-PP showed excellent diagnostic performance compared to culture, with a sensitivity of 94% [95% CI: 87–97] and a specificity of 98% [95% CI: 97–98]. Quantitative concordance improved with higher DNA copies, from 22.9% at the culture threshold at 10⁴ DNA copies/ml in FA-PP to 100% at ≥ 10⁷ DNA copies/ml. Diagnostic performance remained stable during antibiotic treatment with 94% sensitivity and 95% specificity in follow-up ETAs. Conclusions FA-PP provides rapid and accurate diagnostics but does not predict clinical outcomes during treatment, indicating limited utility for repeated testing in patient management.