Effect of nosocomial bloodstream infection on the outcome of critically ill patients with acute renal failure treated with renal replacement therapy

Critically ill patients with acute renal failure (ARF) treated with renal replacement therapy (RRT) have a high mortality. The authors evaluated a cohort of 704 consecutive intensive care unit (ICU) patients with ARF treated with RRT to determine whether there was an increased incidence of nosocomial bloodstream infection and whether this resulted in a worse outcome. The incidence of nosocomial bloodstream infection was 8.8%, higher than that reported in other series of general ICU patients and also higher than the 3.5% incidence of bloodstream infection in non-ARF patients in the same unit (P < 0.001). There were more bloodstream infections caused by Gram-positive species compared with Gram-negative species or fungi. The distribution over the species was comparable to that reported by others for a general ICU population. The outcome was evaluated with matched cohort analysis. With this technique, patients with bloodstream infection (exposed) were closely matched with patients without bloodstream infection (non-exposed) in a 1:2 ratio. Matching was based on the APACHE II system and length of stay before bloodstream infection (exposure time). Length of stay and mortality were equal in exposed and non-exposed patients. There was also no difference in hospital costs. It can be concluded that critically ill patients with ARF treated with RRT were more susceptible to nosocomial bloodstream infection. Nevertheless, the outcome was not influenced by the presence of bloodstream infection. The high mortality observed in ARF patients could therefore not be attributed to the higher incidence of bloodstream infection.