Preoperative chlorhexidine mouthwash to reduce pneumonia after cardiac surgery: A systematic review and meta-analysis.

Objective: Postoperative pneumonia is one of the most common complications after cardiac surgery, entailing increased patient morbidity, mortality, and health care burden. The primary aim of this study was to assess whether preoperative chlorhexidine mouthwash is associated with reduced postoperative pneumonia after cardiac surgery.

Methods: A comprehensive systematic search of NLM Pubmed, Embase, Scopus, and Cumulative Index of Nursing and Allied Health was executed to include the studies since inception to June 27, 2017, which assessed the effects of preoperative chlorhexidine gluconate mouthwash on postoperative pneumonia. Studies were identified by 2 independent reviewers, and data were extracted using a predefined protocol. Random effects models were run to obtain risk ratios with 95% confidence intervals. Quality of evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation criteria. Postoperative pneumonia after cardiac surgery was the primary outcome of the study.

Results: Five studies including a cumulative of 2284 patients were included. A total of 1125 patients received preoperative chlorhexidine. Use of chlorhexidine gluconate was associated with reduced risk of postoperative pneumonia compared with the patients who did not receive it (risk ratio, 0.52; 95% confidence interval, 0.39-0.70; P < .001). No adverse effects from chlorhexidine gluconate mouthwash were reported by any of these studies.

Conclusions: Among the patients receiving preoperative chlorhexidine mouthwash, the risk of postoperative pneumonia is reduced by approximately one-half; its adoption in preoperative protocols could help improve patient outcomes.