Topical chlorhexidine for prevention of ventilator-associated pneumonia: A meta-analysis*

OBJECTIVE: To assess the efficacy of topical chlorhexidine for prevention of ventilator-associated pneumonia (VAP) in a meta-analysis. DATA SOURCE: Computerized PubMed and MEDLINE search supplemented by manual searches for relevant articles. STUDY SELECTION: Randomized controlled trials evaluating efficacy of topical chlorhexidine applied to the oropharynx vs. placebo or standard care for prevention of VAP. DATA EXTRACTION: Data were extracted on patient population, inclusion and exclusion criteria, diagnostic criteria for VAP, form and concentration of topical chlorhexidine used, incidence of VAP, and overall mortality. DATA SYNTHESIS: Data on incidence of VAP and mortality were abstracted as dichotomous variables. Pooled estimates of the relative risk and 95% confidence intervals were obtained using the DerSimonian and Laird random effects model and the Mantel-Haenszel fixed effects model. Heterogeneity was assessed using the Cochran Q statistic and I. Subgroup analyses were used to explore heterogeneity. RESULTS: Seven randomized controlled trials met the inclusion criteria. Topical chlorhexidine resulted in a reduced incidence of VAP (relative risk, 0.74; 95% confidence interval, 0.56-0.96; p=.02) using a fixed effects model. Using the more conservative random effects model, the point estimate was similar (relative risk, 0.70; 95% confidence interval, 0.47-1.04; p=.07), but the results failed to achieve statistical significance. The I test showed moderate heterogeneity. Subgroup analysis showed that the benefit of chlorhexidine was most marked in cardiac surgery patients (relative risk, 0.41; 95% confidence interval, 0.17-0.98; p=.04). There was no mortality benefit with chlorhexidine although the sample size was small. CONCLUSIONS: Our analysis showed that topical chlorhexidine is beneficial in preventing VAP; the benefit is most marked in cardiac surgery patients. A large randomized trial is needed to determine the impact of topical chlorhexidine on mortality.