Randomized controlled trial and meta-analysis of oral decontamination with 2% chlorhexidine solution for the prevention of ventilator-associated pneumonia.

OBJECTIVE To determine the effectiveness of oral decontamination with 2% chlorhexidine solution for the prevention of ventilator-associated pneumonia (VAP). DESIGN Randomized controlled trial and meta-analysis. SETTING A tertiary care university hospital in Bangkok, Thailand. PARTICIPANTS Adult patients who received mechanical ventilation and who were hospitalized in intensive care units and general medical wards. METHODS The patients were randomized to receive oral decontamination with 2% chlorhexidine solution or normal saline solution 4 times per day until their endotracheal tubes were removed. The outcome measures were the development of VAP and oropharyngeal colonization with gram-negative bacilli. Meta-analysis was performed by combining the results of the present study with those from another randomized controlled trial that also used a 2% chlorhexidine formulation for oral decontamination. RESULTS The characteristics of the patients in the chlorhexidine group (n=102) and the normal saline group (n=105) were not significantly different. The incidence of VAP in the chlorhexidine group was 4.9% (5 of 102), and the incidence in the normal saline group was 11.4% (12 of 105) (P=.08). The rate of VAP in the chlorhexidine group was 7 episodes per 1,000 ventilator-days, and the rate in the normal saline group was 21 episodes per 1,000 ventilator-days (P=.04). Irritation of the oral mucosa was observed in 10 (9.8%) of the patients in the chlorhexidine group and in 1 (0.9%) of the patients in the normal saline group (P=.001). Oropharyngeal colonization with gram-negative bacilli was either reduced or delayed in the chlorhexidine group. Overall mortality of the patients did not differ significantly between the groups. Meta-analysis of 2 randomized controlled trials revealed an overall relative risk of VAP for patients in the chlorhexidine group of 0.53 (95% confidence interval, 0.31-0.90; P=.02). CONCLUSION Oral decontamination with 2% chlorhexidine solution is an effective and safe method for preventing VAP in patients who receive mechanical ventilation.