The efficacy of chlorhexidine gluconate in reducing ventilator-associated pheumonia

Respiratory assistance devices bypass essential host defenses and allow these pathogens direct access to the lower respiratory tract and hinder these defense systems to effectively clear respiratory pathogens (1). Mechanical ventilation in the presence of dental plaque with respiratory pathogens has the potential to lead to ventilator-associated pneumonia (VAP). Ventilator-associated pneumonia is the leading cause of morbidity and mortality in intensive care units. VAP influences increasing need for medical treatment and hospital length of stay (LOS) (2-4). Lower respiratory tract infections (LRTI) have been found to be the most expensive site per infection with 13% of all infections accounting for 29% of the total recorded cost (5). The purpose of this systematic review is to perform a comprehensive literature search to identify published randomized clinical trials relating to the efficacy of chlorhexidine gluconate (CHX) oral rinse in preventing VAP. CHX has been identified as the "gold standard" to reduce the number of microorganisms. This review also addresses the importance of oral health and the increased risk of respiratory infections from colonization by harmful pathogens within the oral mucosa. Clinical trials relating to the hypothesis in question were evaluated using Consolidated Standards of Reporting Trials (CONSORT) checklist for validity. Quality and strength of each randomized clinical trial were evaluated based on the requirements of the Agency for Healthcare Research and Quality (AHRQ). Nine bibliographic databases, from 1965-2012 were used to conduct the literature inquiry. Ten studies included populations greater than or equal to 18 years of age and admitted to the intensive care unit receiving mechanical ventilation. The patients were, ventilated due to either trauma, undergoing elective cardiothoracic surgery, or from some other form of surgery, at risk for VAP. In one study, CHX oral rinse decreased microbial colonization of the respiratory tract and hospital-acquired pneumonia (HAP) in patients who underwent open-heart surgery and were intubated less than 24 hours. Yet the difference was not significant in patients intubated more than 24 hours who had a higher amount of bacterial colonization (6). Modulation of oropharyngeal colonization by the use of oral chlorhexidine has reduced the number of ICU-acquired HAP in selected patient populations such as those undergoing coronary bypass grafting, but its routine use is not recommended until more data become available (7). Findings from several studies suggest a significant decrease in the incidence of total nosocomial respiratory infections and systemic antibiotic use in patients who underwent open heart and used a CHX oral rinse as compared with ventilator patients who did not use the rinse; there was also a 65% decrease (13% vs. 4%) in the overall nosocomial infection rate in the chlorhexidine group (7,8,9). Using 2% chlorhexidine solution presents the strongest evidence for decreasing VAP (10,11). From Scannapieco and colleagues' study we can conclude that twice daily is not necessarily better than once daily, but maybe a four times daily regimen with 2% instead of 0.12% CHX does make a difference in reducing the incidence of VAP (12)