Enterococcal bacteremia in the surgical intensive care unit: Does vancomycin resistance affect mortality?

Objective: To determine the incidence and mortality rate associated with nosocomial bacteremia caused by vancomycin-resistant Enterococcus in a surgical intensive care unit. Design: A retrospective study. Setting: The surgical intensive care unit of a large university hospital tertiary referral center. Patients: All patients in the surgical intensive care unit with a documented nosocomial bacteremia between January 1, 1992, and December 31, 1994. Interventions: None. Main Outcome Measure: Mortality rate. Results: Of the 134 nosocomial bacteremic episodes, 30.6% involved enterococci; 24.4% of the enterococci were resistant to vancomycin. Patients with vancomycin-resistant enterococcal bacteremia had a significantly longer hospital stay (mean±SD, 28±18 vs 12±10 days; P=.005) and were more likely to have been treated with vancomycin (70% vs 10.3%; P=.001) than patients with vancomycin sensitive enterococcal bacteremia. The mortality (41.0%) associated with enterococcal bacteremia was similar to the overall bacteremic mortality (41.7%). There was no difference in episode-specific mortality associated with vancomycin-resistant enterococci (40%) vs vancomycin-sensitive enterococci (38.7%). Of the 4 deaths associated with vancomycin-resistant enterococcal bacteremia, only 2 occurred within 14 days of the bacteremia, as did 8 of 12 deaths associated with vancomycin sensitive enterococcal bacteremia (P=.64). Conclusions: Enterococci were the most commonly isolated nosocomial blood-borne pathogens in the surgical intensive care unit. Nearly 25% of the enterococcal bacteremic episodes were resistant to vancomycin. Vancomycin-resistant Enterococcus is associated with a prolonged hospital stay and with vancomycin use. Nevertheless, vancomycin resistance itself does not increase the mortality rate associated with enterococcal bacteremia.