Comparison of RIFLE, AKIN, and KDIGO Classifications for Assessing Prognosis of Patients on Extracorporeal Membrane Oxygenation

Background/purpose: Acute kidney injury (AKI) developing during extracorporeal membrane oxygenation (ECMO) is associated with very poor outcome. The Kidney Disease: Improving Global Outcomes (KDIGO) group published a new AKI definition in 2012. This study analyzed the outcomes of patients treated with ECMO and identified the relationship between the prognosis and the KDIGO classification.

Methods: This study examined total 312 patients initially, and finally reviewed the medical records of 167 patients on ECMO support at a tertiary care university hospital between March 2002 and November 2011. Demographic, clinical, and laboratory variables were retrospectively collected as survival predicators.

Results: The overall mortality rate was 55.7%. In the analysis of the areas under the receiver operating characteristic curves, the KDIGO classification showed relatively higher discriminatory power (0.840 ± 0.032) than the Risk of renal failure, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage renal failure (RIFLE) (0.826 ± 0.033) and Acute Kidney Injury Network (AKIN) (0.836 ± 0.032) criteria in predicting in-hospital mortality. Furthermore, multiple logistic regression analysis showed that KDIGO, hemoglobin, and Glasgow Coma Scale score on the first day of patients on ECMO were independent predictors for in-hospital mortality. Finally, cumulative survival rates at 6-month follow-up after hospital discharge differed significantly for KDIGO stage 3 versus KDIGO stage 0, 1, and 2 (p < 0.001); and KDIGO stage 2 versus KDIGO stage 0 (p < 0.05).

Conclusion: For those patients with ECMO support, the KDIGO classification proved to be a more reproducible evaluation tool with excellent prognostic abilities than RIFLE or AKIN classification.