Mortality risk factors of Acinetobacter baumannii bacteraemia

Background: Acinetobacter baumannii is one of the most important nosocomial pathogens, and its multiple antibiotic resistance has emerged as an obstacle in the treatment of these infections worldwide. Aims: To identify risk factors of mortality for A. baumannii bacteraemia. Methods: A retrospective cohort study of 72 patients with significant A. baumannii bacteraemia was conducted to evaluate risk factors for mortality. Results: The median age of the 72 enrolled patients was 48 years, 96% of the cases were hospital-acquired, and the bacteraemia-related mortality rate was 29% (21 of 72 patients). Univariate analysis revealed that the risk factors for mortality included: an elevated acute physiology and chronic health evaluation (APACHE II) score, receipt of in vitro ineffective definitive antimicrobial therapy, in vitro A. baumannii resistance to cefoperazone/ sulbactam, neutropenia, and presentation with septic shock. Multivariate analysis reveals that the independent risk factors for mortality are neutropenia and elevated APACHE II scores. Conclusion: Risk factors such as neutropenia and elevated APACHE II scores are found to be associated with higher mortality rates of A. baumannii bacteraemia. Further study is necessary for the determination of optimal strategies for both the prevention and treatment of these infections. (Intern Med J 2005; 35: 599–603)