Risk factors and outcome in patients with bacteraemia secondary to ventilatoraAssociated pneumonia due to acinetobacter baumannii

Abstract

Introduction: Acinetobacter baumannii is a multi-drug resistant (MDR), gram -negative, infectious nosocomial pathogen, commonly affecting critically ill patients admitted to intensive care units (ICU). Patients with ventilator -associated pneumonia (VAP) may contract A. baumannii bacteremia, which may significantly impair prognosis. This study evaluates the risk factors and outcomes in patients with bacteremia secondary to VAP. Materials and Methods: Two hundred thirty one VAP and bacteremia attacks secondary to VAP due to A. baumannii, followed in intensive care units over a six-year period, were examined. Risk factors and outcomes were compared from patient records. Results: The median age and gender distribution of the episodes were similar. In the bacteremia group, the ratio of peripheral venous catheterizations and total parenteral nutrition (TPN) use was significantly higher than in the non-bacteremia group (p= 0.001 vs. p< 0.001, respectively). The median APACHE-II score in the bacteremia group was significantly higher than in the non-bacteremia group (28 vs. 24, respectively, p< 0.001). However, median SOFA 1 (SOFA at ICU admission) and SOFA 2 (SOFA at diagnosis) scores did not differ from those in the non-bacteremia group (6 vs. 5, respectively, p= 0.173 and 9 vs. 9, respectively, p= 0.088). There was no significant difference observed in the distribution of the Charlson comorbidity index between the groups. The incidence of mortality was 2.8 times higher in the bacteremia group compared to the non-bacteremia group. Conclusion: Total parenteral nutrition and venous catheterization are identified as risk factors for bacteremia in patients with VAP caused by A. baumannii, with a 2.4 and 2.2 fold increase, respectively. While SOFA 1 and SOFA 2 scores may not hold significance in the presence of bacteremia, the APACHE-II score alone may be significant. Additionally, prolonged and unsupervised use of proton pump inhibitors (PPI) in critically ill ICU patients may elevate the risk of bacteremia and associated mortalities in VAP patients.