A comparison of acute kidney injury classification systems in sepsis

Abstract

Background: Since 2004, various criteria have been proposed to define and grade acute kidney injury (AKI). Nevertheless, fixed criteria for assessing severe sepsis-related AKI have not yet been established. Objectives: To assess the power of the different methods of AKI classification to predict mortality in a cohort of patients with sepsis. Methods: A prospective study of patients > 18 years with septic shock admitted to the intensive care unit (ICU) of our hospital from April 2008 to September 2010 was conducted. Plasma creatinine levels were measured daily. Patients were classified retrospectively according to RIFLE, AKIN, KDIGO and creatinine kinetics (CK) criteria. Results: The percent of AKI rate according to the different criteria was 74.3% for RIFLE, 81.7% for AKIN, 81.7% for KDIGO and 77.5% for CK. AKI staging by RIFLE (OR 1.452, p = 0.003), AKIN (OR 1.349, p = 0.028) and KDIGO criteria (OR 1.452, p = 0.006), but not CK criteria (OR 1.188, p = 0.148) were independently related to in-hospital mortality. Conclusions: A high rate of patients with severe sepsis developed AKI, which can be classified according to different criteria. Each stage defined by RIFLE, AKIN and KDIGO related to a higher risk of in-hospital mortality. In contrast, the new CK criteria did not relate to higher mortality in patients with severe sepsis and this classification should not be used in these patients without having validated its suitability with further studies.

Keywords

• Acute kidney injury
• Mortality
• Sepsis