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

Abstract

BACKGROUND:

The impact of antibiotic resistance on the outcome of infections due to Gram-negative bacilli, especially Pseudomonas, remains highly controversial. STUDY OBJECTIVE, DESIGN, AND PATIENTS: 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 days of antibiotics.

RESULTS:

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 = 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.

CONCLUSIONS:

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.

• Authors: Alain Combes, Charles-Edouard Luyt, Jean-Yves Fagon, Michel Wolff, Jean-Louis Trouillet, Jean Chastre
• Journal: Intensive care medicine (Intensive Care Med) Vol. 32 Issue 12 Pg. 1970-8 (Dec 2006) ISSN: 0342-4642 [Print] United States
• PMID: 16957901 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial)

Chemical References

• Anti-Bacterial Agents
• Piperacillin

Topics

• Aged
• Anti-Bacterial Agents (therapeutic use)
• Bronchoscopy
• Drug Resistance, Bacterial
• Female
• Humans
• Intensive Care Units
• Logistic Models
• Male
• Middle Aged
• Outcome Assessment, Health Care
• Piperacillin (therapeutic use)
• Pneumonia, Ventilator-Associated (drug therapy, microbiology, mortality)
• Pseudomonas Infections (drug therapy, mortality, physiopathology)
• Pseudomonas aeruginosa (drug effects, pathogenicity)
• Severity of Illness Index