Polymicrobial bacteremia in critically ill patients

Objective To characterize the epidemiology of polymicrobial bacteremia (PMB) among critically ill patients.Design Prospective clinical study.Setting University medical center.Patients All patients with positive blood cultures in a medical-surgical ICU.Measurements PMB represents 8.4% of all true bacteremia in our ICU. Most of these patients were post-operative but none had malignancies or significant immunodepression. Over three-quarters of the episodes were nosocomial. No significant differences in factors associated with PMB were found when they were compared with a cohort of 154 monomicrobial episodes. Enterobacteriaceae were the most common organisms. Intravascular devices (42.8%) were the most common source of PMB, followed by intra-abdominal origin (21.4%). The overall mortality was 7.1%, a lower rate than has previously been described.Conclusions We suggest catheter replacement in patients who develop PMB and improving techniques of catheter maintenance in order to reduce its incidence.