Pseudomonas Aeruginosa Ventilator-Associated Pneumonia: Predictive Factors of Treatment Failure.
Résumé
Introduction. The predictive factors of treatment failure for Ventilator-Acquired Pneumonia (VAP) due to Pseudomonas aeruginosa (PA) remain uncertain. Methods. From the multicenter Outcomerea database (1997-2011), PA-VAP onset and recurrence were recorded. All suspected VAP were confirmed by a positive quantitative culture of a respiratory sample. Multidrug resistant PA strains was defined by the resistance to 2 antibiotics among piperacillin, ceftazidime, imipenem, colistine and fluoroquinolones (FQ). An extensively resistant (XDR) PA was defined by resistance to piperacillin, ceftazidime, imipenem, and FQ. A treatment failure was defined as a PA-VAP recurrence or by the death occurrence. Results. 314 patients presented 393 PA-VAP. Failure occurred for 112 of them, including 79 recurrences. Susceptible, MDR and XDR PA represented 53.7%, 32% and 14.3% of the samples, respectively. Factors associated with treatment failure were: age (p=0.02), presence of at least one chronic illness (p=0.02), limitation of life support (p=0.0004), a high SOFA score (p<.0001), PA-bacteremia (p=0.003) and previous use of FQ before the first PA-VAP (p=0.0007). The failure risk was not influenced by the strain resistance profile or by the bi-antibiotic treatment, but decreased in case of VAP treatment that includes FQ (subdistribution hazard ratio sHR 0.5 [0.3-0.7]; p=0.0006). However, the strain resistance profile slows down the ICU discharge hazard (sHR 0.6 [0.4-1.0] p=0.048). Conclusion. Neither resistance profile nor bi-antibiotic therapy decreased the risk of PA-VAP treatment failure. However, the profile of PA resistance prolonged the length of stay. The potential benefit of an initial treatment containing FQ needs further randomized trials.