Application of the sequential organ failure assessment (SOFA) score to bacteremic ICU patients

Abstract

Background: Patients admitted to intensive care units (ICUs) are at a high risk of acquiring blood stream infections. We examined whether SOFA score on ICU admission and on the day of bacteremia can predict the occurrence of bacteremia and the outcome of bacteremic ICU patients.

Patients and methods: All patients admitted to a multidisciplinary ICU for more than 48 h from January 1, 2002 to December 31, 2004, were prospectively studied. Demographic, clinical and laboratory data were recorded on admission for all patients and additionally, on the day of the first bacteremic episode for those patients who developed bacteremia. Accordingly, APACHE II and SOFA scores were calculated on the same day.

Results: A total of 185 patients developed one or more episodes of bacteremia, giving an incidence of 9.6 per 1,000 ICU days. The ICU mortality rate was 43.9% for bacteremic and 25.8% for the remaining patients (p < 0.001). Admission SOFA score was independently associated with the occurrence of bacteremia (OR = 1.20, 95% CI: 1.11-1.26, p < 0.001). Among bacteremic patients, SOFA score on the day of bacteremia was the only independent prognostic factor for outcome (OR = 1.44, 95% CI: 1.21-1.71, p < 0.001). When all patients were included in the multivariate analysis, admission SOFA (OR = 1.3, CI: 1.16-1.38, p < 0.001), APACHE II (OR = 1.1, CI: 1.02-1.11, p = 0.003) score and the presence of bacteremia (OR = 1.8, CI: 1.1-2.9, p = 0.023) were independently associated with the outcome.

Conclusion: Admission SOFA score is independently associated with the occurrence of ICU-acquired bacteremia, whereas it is not sufficient to predict the outcome of patients who subsequently will develop this complication. However, SOFA score on the first day of bacteremia is an independent prognostic factor for outcome in these patients.