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.