Friday, September 08, 2006

Impact of piperacillin resistance on the outcome of Pseudomonas ventilator-associated pneumonia.

Impact of piperacillin resistance on the outcome of Pseudomonas ventilator-associated pneumonia.

Sept 7, 2006

Combes A,
Luyt CE,
Fagon JY,
Wolff M,
Trouillet JL,
Chastre J.

Groupe Hospitalier Pitie-Salpetriere, Assistance Publique, Hopitaux de Paris Universite Pierre et Marie Curie, Paris 6, Service de Reanimation Medicale, Institut de Cardiologie, 47, boulevard de l'Hopital, 75651, Paris Cedex 13, France,


The impact of antibiotic resistance on the outcome of infections due to Gram-negative bacilli, especially Pseudomonas, remains highly controversial.


We evaluated the impact of piperacillin resistance on the outcomes of Pseudomonas aeruginosa ventilator-associated pneumonia (VAP) for patients who had received appropriate empiric antibiotics before enrollment in the PNEUMA trial, a multicenter randomized study comparing 8 vs 15[Symbol: see text]days of antibiotics.


Despite similar characteristics at intensive care unit (ICU) admission, patients infected with piperacillin-resistant Pseudomonas strains were more acutely ill at VAP onset and had a higher 28-day mortality rate (37 vs 19%; P[Symbol: see text]=[Symbol: see text]0.04) than those with piperacillin-susceptible Pseudomonas VAP. Factors associated with 28-day mortality retained by multivariable analysis were: age (OR: 1.07; 95% CI: 1.03-1.12); female gender (OR: 4.00; 95% CI: 1.41-11.11); severe underlying comorbidities (OR: 2.73; 95% CI: 1.02-7.33); and SOFA score (OR: 1.17; 95% CI: 1.03-1.32), but piperacillin resistance did not reach statistical significance (OR: 2.00; 95% CI: 0.72-5.61). The VAP recurrence rates, either superinfection or relapse, and durations of mechanical ventilation and ICU stay did not differ as a function of Pseudomonas-resistance status.


For patients with Pseudomonas VAP benefiting from appropriate empiric antibiotics, piperacillin resistance was associated with increased disease severity at VAP onset and higher 28-day crude mortality; however, after controlling for confounders, piperacillin-resistance was no longer significantly associated with 28-day mortality. The VAP recurrence rates and durations of ICU stay and mechanical ventilation did not differ for susceptible and resistant strains.

PMID: 16957901
[PubMed - as supplied by publisher]