Effectiveness of 0.12% chlorhexidine gluconate oral rinse in reducing prevalence of nosocomial pneumonia in patients undergoing heart surgery.

BACKGROUND Decreasing the levels of bacteria in the oropharynx should reduce the prevalence of nosocomial pneumonia. OBJECTIVES To test the effectiveness of 0.12% chlorhexidine gluconate oral rinse in decreasing microbial colonization of the respiratory tract and nosocomial pneumonia in patients undergoing open heart surgery. METHODS A prospective, randomized, case-controlled clinical trial design was used. Peridex (0.12% chlorhexidine gluconate) was the experimental drug, and Listerine (phenolic mixture) was the control drug. A total of 561 patients undergoing aortocoronary bypass or valve surgery requiring cardiopulmonary bypass were randomized to an experimental (n = 270) or a control (n = 291) group. Nosocomial pneumonia was diagnosed by using the criteria established by the Centers for Disease Control and Prevention. RESULTS The overall rate of nosocomial pneumonia was reduced by 52% (4/270 vs 9/291; P = .21) in the Peridex-treated patients. Among patients intubated for more than 24 hours who had cultures that showed microbial growth (all pneumonias occurred in this group), the pneumonia rate was reduced by 58% (4/19 vs 9/18; P = .06) in patients treated with Peridex. In patients at highest risk for pneumonia (intubated > 24 hours, with cultures showing the most growth), the rate was 71% lower in the Peridex group than in the Listerine group (2/10 vs 7/10; P = .02). CONCLUSIONS Although rates of nosocomial pneumonia were lower in patients treated with Peridex than in patients treated with Listerine, the difference was significant only in those patients intubated more than 24 hours who had the highest degree of bacterial colonization.