Reduction of Microbial Colonization in the Oropharynx and Dental Plaque Reduces Ventilator-Associated Pneumonia

BACKGROUND: An estimated 150,000–300,000 cases of nosocomial pneumonia occur each year in U.S. hospitals. The primary risk factor for nosocomial bacterial pneumonia is mechanical ventilation using an endotracheal tube. Ventilator-associated pneumonia (VAP) outcomes can be severe, with mortality reaching 87%. VAP also extends length of stay by an average of 6 days and can cost >$40,000 per event. The scientific literature provides strong evidence of an association between oropharyngeal and dental plaque colonization and respiratory infection. OBJECTIVES: To determine the effectiveness of a comprehensive program of oral and dental health assessment and intervention to reduce the rates of VAP. METHODS: All adult patients placed on mechanical ventilation using an endotracheal tube in the medical intensive care unit (MICU) during January 2002–December 2003 were included in the study. Patients intubated between January–December 2002 (pre-intervention) received standard oral care. For the period January–December 2003 (post-intervention), nurses were required to assess the daily condition of the lips, oral tissues, tongue, teeth, and saliva. Review of practices revealed a need for improved interventions. A new oral-dental care kit with universal adaptor was introduced that provided 1) a closed oral/tracheal suction system; 2) covered yankauer to reduce environmental contamination; 3) subglottic suctioning catheters for secretions pooled above the endotracheal cuff (q6h); 4) suction toothbrush with hydrogen peroxide solution to reduce dental plaque (2x day); 5) suction oral swab with moisturizer to promote mucosal integrity (q4h). No other interventions were introduced during the study period. RESULTS: Patient ages, sex, and diagnoses were similar in the pre-intervention group and the study group. The number of patients and ventilator days were 414 and 2,610 (average 6.3 days) for the pre-intervention group and 364 and 2,379 (average 6.5 days) for the patients using the new intervention. Risk for pneumonia in both years was high: ventilator utilization ratio (VUR) for the MICU was 0.63 in 2002 and 0.55 in 2003, or approximately 75th-90th percentile of NNIS data. Rate of VAP per 1000 ventilator days in the MICU was 7.7 in 2002 and 4.6 in 2003, a 40.3% reduction in the overall rate (p <0.01). NNIS benchmark data indicates median MICU VAP rates at 6.0 per 1000 ventilator days. CONCLUSION: Careful assessment and improved oral care interventions to reduce bacterial colonization of the oropharynx and teeth reduces contaminated aspirates and subsequent VAP.