The incidence of nosocomial bloodstream infections in our cardiac surgical intensive care unit during a three-year period

Objectives: Nosocomial bloodstream infections (BSI) cause significant morbidity and mortality worldwide. These infections occur two to seven times more often in intensive care unit (ICU) patients than in ward patients. The aim of this study was to determine the frequency of nosocomial BSI pathogens among patients admitted to our 18-bed cardiac surgical ICU (SICU). Study design: We investigated SICU-acquired BSIs and associated pathogens in 1316 patients (886 adult, 430 pediatric) admitted to the cardiac SICU following cardiac operations between January 2000 and December 2002. Results: A total of 93 microorganisms of nosocomial BSIs were identified in 60 patients (4.6%), including both primary (38.3%) and secondary BSIs. Of these, 36 were adult patients (60%), and 24 were pediatric patients (40%). Secondary BSIs were due to intravascular devices (23.3%), lower airway tract infections (20%), surgical wound infections (8.4%), urinary tract infections (5%), and other causes (5%). The most frequently isolated species were coagulase-negative staphylococci (30%), Pseudomonas aeruginosa (8.4%), and Acinetobacter baumannii (6.7%). The most common cardiac surgical procedures associated with BSI were congenital cardiac operations (40%), followed by coronary artery bypass grafting procedures (33.3%). The overall mortality rate was 4.5% (59 patients). Mortality was six-fold higher in patients with BSI (14 patients, 23.3%) than those without BSI. Conclusion: Our study emphasizes the importance of infection prevention and identification of pathogens leading to BSIs in cardiac SICU patients.