Acute kidney disease stage predicts outcome of patients on extracorporeal membrane oxygenation support

Background The mortality rate of patients on extracorporeal membrane oxygenation (ECMO), especially those patients that develop acute kidney injury (AKI) is high. Acute kidney disease (AKD) is a term used to describe the continuum from AKI to chronic kidney disease. However, the role of AKD in predicting the prognosis of patients on ECMO support is unclear. Methods A total of 168 patients who received ECMO support and survived for more than 7 days at a single hospital from 2003 to 2008 were enrolled for this study and followed up for 10 years or till mortality. Kaplan-Meier analysis and Cox proportional hazards model were used to determine the prognostic factors associated with survival. Results The median survival times of patients with stage 0, stage 1, stage 2 and stage 3 AKD were >= 10 years, 43.9 months, 1 month, and half a month, respectively. There were statistically significant differences in cumulative survival rate between patients with stage 3 AKD and those with stage 0, 1, and 2 AKD (Cox-Mantel log rank test, p<0.001, p<0.001, p = 0.023), and between patients with stage 0 AKD and those with stage 1 and 2 AKD (Cox-Mantel log rank test, p = 0.012, p<0.001). Cox regression analysis revealed that AKD stage (hazard ratio [HR]: 2.576, 95% confidential interval [CI]: 1.268-5.234, p = 0.009 for stage 1; HR: 2.349; 95% CI: 1.101-5.512, p = 0.029 for stage 2; HR: 5.252; 95% CI: 2.715-10.163, p<0.001 for stage 3) was significant independent predictor of survival. Conclusion AKD stage is an independent predictor of survival in patients on ECMO support.