Introduction The objective of this study was to compare bacteremic and non-bacteremic ventilator associated pneumonia (B-VAP and NB-VAP) in terms of risk factors, organisms and outcomes.

Methods A retrospective, single center, observational, cohort study was performed in a pediatric intensive care unit. All patients, requiring mechanical ventilation, and identified as having VAP in a 4-year prospective surveillance database (2004–2007) were included. Criteria of the CDC were used for the diagnosis of B-VAP and NB-VAP. The two groups were compared in terms of risk factors, organisms and outcomes.

Results During the study period, 39 patients developed 40 episodes of VAP, accounting for an incidence rate of 3.5 per 100 admissions and a density incidence rate of 3.2 per 1000 patient-days. B-VAP was documented in 11 patients (27.5%) of the 40 microbiologically confirmed VAP episodes. B-VAP occurred later than NB-VAP (18.5±15.9 vs 8.4±3.5 days; p = 0.002). There was no difference between the two groups concerning the use of antibiotherapy, invasive procedures and sedation.

Pseudomonas aeruginosa, involved in 27.2% of bacteremic episodes and 31% of non-bacteremic episodes, was the most common organism causing VAP in the two groups. The mortality rate was higher in the Bacteremic group (63.6% vs 20.7%; p = 0.02). The estimated relative risk of death for bacteremic cases was 3.6 (95% CI 1.3 to 10.2).

Conclusion B-VAP occurred later during intensive care unit stay, was often caused by Pseudomonas aeruginosa and was associated with increased intensive care unit mortality.