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 postoperative 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.