Analysis of progression in risk, injury, failure, loss, and end-stage renal disease classification on outcome in patients with severe sepsis and septic shock.

INTRODUCTION: A few studies have assessed risk, injury, failure, loss, and end-stage renal disease (RIFLE) criteria in patients with severe sepsis and septic shock, a setting in which acute kidney injury (AKI) is common and dramatically worsens outcome.
METHODS: Study subjects included all consecutive patients with severe sepsis and septic shock who had been admitted to the medical intensive care unit between January 2005 and December 2006.
RESULTS: Of 326 patients admitted during the study period, 291 were included. According to RIFLE criteria, 204 patients (70.1%) had AKI (risk, 26.1%; injury, 26.5%; failure, 17.5%) on admission. Overall, 28-day mortality rate was 48.5%. Mortality was not associated with admission RIFLE (risk, 44.7%; injury, 53.2%; failure, 51.0%; P = .58). However, maximum RIFLE was associated with increased 28-day mortality (P < .01). After adjustment for age, sex, Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score, independent risk factors for 28-day mortality were newly developed AKI (odds ratio [OR], 11.4; P < .01), progression of RIFLE risk to higher RIFLE class (OR, 14.5; P < .01), maximum RIFLE injury (OR, 5.58; P < .01), and maximum RIFLE failure (OR, 7.64; P < .01).
CONCLUSIONS: Progression of RIFLE class and newly developed AKI after hospital admission were better able to predict 28-day mortality than RIFLE criteria on the first day of admission in patients with severe sepsis and septic shock.