Incidence and Outcomes of Ventilator-Associated Pneumonia in Japanese Intensive Care Units: The Japanese Nosocomial Infection Surveillance System

Abstract

Objectives.To determine the incidence of ventilator-associated pneumonia (VAP) among intensive care unit (ICU) patients in Japan and to assess the impact of VAP on patient outcomes, including mortality, length of stay, and duration of mechanical ventilation.Design.Multicenter cohort study.Setting.Twenty-eight ICUs in multidisciplinary Japanese hospitals with more than 200 beds.Patients.A total of 21,909 patients 16 years or older who were admitted to an ICU between June 2002 and June 2004, stayed in the ICU for 24 to 1,000 hours, and were not transferred to another ICU.Results.The overall infection rates for nosocomial pneumonia and VAP were 6.5 cases per 1,000 patient-days and 12.6 cases per 1,000 ventilator-days, respectively. The standardized mortality rates for the patients with VAP was 1.3 (95% confidence interval [CI], 1.1-1.6): 1.1 (95% CI, 0.9-1.4) for the cases due to drug-susceptible pathogens and 1.5 (95% CI, 1.1-1.9) for the cases due to drug-resistant pathogens. After adjusting for Acute Physiology and Chronic Health Evaluation II score, the mean length of stay for the patients with VAP caused by drug-susceptible pathogens (15.2 days [95% CI, 14.6-15.8]) and by drug-resistant pathogens (17.8 days [95% CI, 17.0-18.6]) was significantly longer than that in the patients without nosocomial infection (6.8 days [95% CI, 6.7-6.9]). The mean duration of mechanical ventilation in the patients with VAP caused by drug-susceptible pathogens (12.0 days [95% CI, 11.5-12.5]) and drug-resistant pathogens (14.1 days [95% CI, 13.5-14.8]) was significantly longer than that in the patients without nosocomial infection (4.7 days [95% CI, 4.6-4:8]).Conclusion.The incidence of VAP is substantial among ICU patients in Japan. The potential impact of VAP on patient outcomes emphasizes the importance of preventive measures against VAP, especially for VAP caused by drug-resistant pathogens.