RESEARCH ARTICLE Open Access

outcomes of ICU-acquired infections caused by Gram-negative bacteria in critically ill patients: an observational, retrospective study Cosimo Chelazzi*, Eleonora Pettini, Gianluca Villa and A. Raffaele De Gaudio Background: Gram-negative bacteria are increasingly responsible for nosocomial infections, including ICU-acquired infections. Due to high virulence, rate of multi-drug resistance and limited availability of new agents, these infections create cumbersome clinical burdens, making it important to reduce the risk of their occurrence. The aim of the study was to assess epidemiology-related factors and outcomes of Gram-negative, ICU-acquired infections in a cohort of medical-surgical patients. Methods: A retrospective survey was conducted on all patients admitted to a mixed ICU from January 2012 to December 2013. ‘ICU-acquired infections ’ were defined as new infections acquired no less than 48 h after ICU admission. Diagnosis was made according to the Centers for Disease Control and Prevention National Healthcare Safety Network (CDC/NHSN) criteria. Differences across patients who did and did not acquire a Gram-negative infection were tested regarding age, sex, body mass index, medical or surgical admission, cardiovascular comorbidities, chroni