Xuying Luo, Li Jiang, Bin Du, Ying Wen, Meiping Wang, Xiuming Xi; Critical Care 2014, 18:R144 (8 July 2014)

Introduction: Recently, the Kidney Disease: Improving Global Outcomes (KDIGO) proposed a new definition and classification of acute kidney injury (AKI) based on the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage renal failure) and AKIN (Acute Kidney Injury Network) criteria but the comparison of three criteria in critically ill patients is rare.

Methods: We prospectively analyzed a clinical database of 3,107 adult patients who were consecutively admitted to 30 Intensive Care Units of 28 tertiary hospitals in Beijing, from 1 March 2012 to 31 August 2012. AKI was defined by the RIFLE, AKIN and KDIGO criteria. Receiver operating curves were used to compare the predictive ability for mortality, and logistic regression analysis for the calculation of odds ratio (OR) and 95% confidence intervals (CIs).

Results: The incidence of AKI using the RIFLE, AKIN and KDIGO criteria was 46.9%, 38.4% and 51%, respectively. KDIGO identified more patients than RIFLE (51% versus 46.9%, P = 0.001) and AKIN (51% versus 38.4%, P <0.001). Compared to patients without AKI, in-hospital mortality was significantly higher for those diagnosed as AKI using the RIFLE (27.8% versus 7%, P <0.001), AKIN (32.2% versus 7.1%, P <0.001) and KDIGO criteria (27.4% versus 5.6%, P <0.001), respectively. There was no difference in AKI-related mortality between RIFLE and KDIGO (27.8% versus 27.4%, P = 0.815), but significant difference between AKIN and KDIGO (32.2% versus 27.4%, P = 0.006). The area under the receiver operator characteristic curve (AUC) for in-hospital mortality was 0.738 (P <0.001) for RIFLE, 0.746 (P < 0.001) AKIN and 0.757 (P <0.001) for KDIGO. KDIGO was more predictive than RIFLE for in-hospital mortality (P <0.001), but there was no difference between KDIGO and AKIN (P = 0.12).

Conclusions: A higher incidence of AKI was diagnosed according to KDIGO criteria. Patients diagnosed as AKI had a significantly higher in-hospital mortality than non-AKI patients, no matter which criteria was used. Compared to the RIFLE criteria, KDIGO was more predictive for in-hospital mortality; but there was no significant difference between AKIN and KDIGO.

Weblink here