Short- Versus Long-Duration Antibiotic Regimens for Ventilator-Associated Pneumonia

The use of shorter antibiotic regimens (7-8 days) for ventilator-associated pneumonia (VAP) may help reduce adverse drug effects, prevent proliferation of multidrug resistant organisms, and decrease costs. Dimopoulos and colleagues performed a systematic review and meta-analysis to determine if shorter therapeutic antimicrobial regimens for VAP were associated with adverse outcomes.

Multiple searches were executed to identify randomized controlled trials involving patients with VAP who were treated with short- (up to 8 days) or long-course (at least 10 days) antimicrobial regimens. Studies were graded for quality with the Jadad score. The primary outcomes of interest were mortality, antibiotic-free days, and relapses. Multiple secondary outcomes were also assessed. Fixed and random effects models were used to calculate pooled odds ratios and 95% confidence intervals.

After 928 articles were retrieved, four randomized controlled trials met the criteria for inclusion in the meta-analysis. Two of the four trials were conducted in France. No difference in mortality was identified between the regimens (odds ratio,1.20; 95% confidence interval, 0.84 to 1.72; P=0.32). Two of the four trials reported data regarding antibiotic-free days; these days were significantly increased in the short-treatment studies. There was no difference in relapses between the regimens, though a near-significant finding of lower relapse rates was observed in the long-duration arms (P=0.06). In terms of secondary outcomes, no difference was seen in ventilator-free days, duration of mechanical ventilation, or length of intensive care unit stay.

This meta-analysis included studies of good overall quality, with the French PneumA study by Chastre et al contributing the bulk of the patients. The number of studies was small, and the 883 patients may have included some with pathogens less likely to lead to relapse. Furthermore, the definition of relapse was driven mainly by the influence of the PneumA study, which used a liberal definition to define recurrent VAP. Although more work is required to define the optimal duration of antibiotic treatment, based on the results of this review, a shorter course (7-8 days) is associated with more antibiotic-free days, equivalent mortality, and no difference in rate of relapse. Patients infected with organisms associated with higher relapse rates and multidrug resistance (i.e., Pseudomonas aeruginosa) may require a longer course of treatment.

Samuel M. Galvagno Jr., DO, PhD, is editor of Concise Critical Care Appraisal. An assistant professor at the University of Maryland, R Adams Cowley Shock Trauma Center, he is board certified in anesthesiology, critical care medicine, and public health.

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