An Observational Veneto Research on Ventilator-Associated Pneumonia (OVeRVAP): attributable mortality and cumulative incidence of ventilator-associated pneumonia.

BACKGROUND: The relationship between ventilator-associated pneumonia (VAP) and mortality varies from study to study, and its entity is uncertain due a considerable variation in the attributable mortality. The aim of this study was to evaluate the relationship between VAP frequency and mortality in a cohort of mechanically ventilated patients. METHODS: A multicenter prospective observational study was conducted in 21 Intensive Care Units (ICUs). The patients were recruited from 2008 to 2010 within randomly selected periods. 842 patients of 2595 admitted, met the eligibility criteria and were enrolled in the study. The study's primary outcome was death by any cause in one of the ICUs. We modelled VAP occurrence as a time-dependent covariate and fitted a competing risk analysis model. We estimated the attributable mortality of VAP as the population-attributable fraction of ICU mortality. RESULTS: A total of 121 patients developed VAP (14.4%), for an incidence rate of 15.7 cases per 1000 ventilator days; of the 175 patients (20.8%) who died during the study period, 31 (25.6%) had VAP. The ICU mortality rate in the patients who developed VAP was 22.6 per 1000 ventilator days (95% CI: 15.9-32.1). We estimated an attributable mortality of 8.4%. CONCLUSIONS: In 8.4% of cases, VAP was the leading cause of death in our study. This indicates that the patients died more frequently with VAP rather than because of it.

Risk factors for ventilator-associated pneumonia by Pseudomonas aeruginosa in presence of recent antibiotic exposure.

BACKGROUND: To facilitate the decision-making process for therapy and prevention of ventilator-associated pneumonia (VAP) in patients undergoing recent antibiotic exposure, this study investigated whether the development of VAP episodes caused by Pseudomonas aeruginosa or other pathogens are related to different risk factors, thereby distinguishing two risk population for this serious complication. METHODS: A 5-year retrospective case-control observational study was conducted. Cases of VAP caused by P. aeruginosa were compared with those caused by other pathogens. Univariate and multivariate analysis was performed using SPSS 11.0 software (SPSS Inc., Chicago, IL). RESULTS: Two groups were identified: P. aeruginosa (group P) was isolated in 58 (63.7%) episodes, and 33 episodes served as controls (group C), after a median of 12 days (interquartile range, 4-28 days) and 9 days (interquartile range, 3-12.5 days) of mechanical ventilation, respectively. P. aeruginosa was identified in 34.7% of episodes with early-onset pneumonia and in 73.5% with late-onset pneumonia. In a logistic regression analysis, P. aeruginosa was independently associated with duration of stay of 5 days or longer (relative risk = 3.59; 95% confidence interval, 1.04-12.35) and absence of coma (relative risk = 8.36; 95% confidence interval, 2.68-26.09). Risk for pathogens different from P. aeruginosa (group C) in early-onset pneumonia associated with coma was estimated to be 87.5%. CONCLUSIONS: Risk factors in episodes under recent antibiotic treatment caused by P. aeruginosa or other microorganism are not the same, a fact that could have implications for preventive and therapeutic approaches for this infection.