Impact of Oral Chlorhexidine on Bloodstream Infection in Critically Ill Patients: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives Oropharyngeal overgrowth of microorganisms in the critically ill is a risk factor for lower respiratory tract infection and subsequent invasion of the bloodstream. Oral chlorhexidine has been used to prevent pneumonia, but its effect on bloodstream infection never has been assessed in meta-analyses. The authors explored the effect of oral chlorhexidine on the incidence of bloodstream infection, the causative microorganism, and on all-cause mortality in critically ill patients. Design Systematic review and meta-analysis of published studies. Setting Intensive care unit. Participants The study comprised critically ill patients receiving oral chlorhexidine (test group) and placebo or standard oral care (control group). Interventions PubMed and the Cochrane Register of Controlled Trials were searched. Odds ratios (ORs) were pooled using the random-effects model. Measurements and Main Results Five studies including 1,655 patients (832 chlorhexidine and 823 control patients) were identified. The majority of information was from studies at low or unclear risk bias; 1 study was at high risk of bias. Bloodstream infection and mortality were not reduced significantly by chlorhexidine (OR 0.74; 95% confidence interval [CI] 0.37-1.50 and OR 0.69; 95% CI 0.31-1.53, respectively). In the subgroup of surgical, mainly cardiac, patients, chlorhexidine reduced bloodstream infection (OR 0.47; 95% CI 0.22-0.97). Chlorhexidine did not affect any microorganism significantly. Conclusion In critically ill patients, oropharyngeal chlorhexidine did not reduce bloodstream infection and mortality significantly and did not affect any microorganism involved. The presence of a high risk of bias in 1 study and unclear risk of bias in others may have affected the robustness of these findings.