The impact of different stages of aki on mortality and discharge outcomes for patients on va ecmo

Introduction: Chronic kidney disease has been shown to be an independent risk factor in hospital mortality for patients on venoarterial extracorporeal membranous oxygenation (VA ECMO). The impact of the degree of acute kidney injury (AKI) as per Kidney Disease Improving Global Outcomes (KDIGO) criteria while patients are receiving VA ECMO on patient outcomes has yet to be elucidated. Methods: We performed a retrospective, single center study of a high-volume ECMO and cardiac surgery center from January 2017 to December 2021. We collected patient demographics, comorbidities, degree of AKI, and patient outcomes including mortality and hospital discharge status with regards to renal replacement therapy (RRT). We compared the outcomes amongst the different stages of AKI by performing a Chi-squared test for categorical variables and ANOVA test for continuous variables. Results: 179 patients were identified for our analysis after exclusion. Among these patients, 66 patients had stage 0 AKI, 19 patients had stage I AKI, 18 patients had stage II AKI, and 76 patients had stage III AKI. With an unadjusted analysis, stage 0 AKI demonstrated 50% (33/66) mortality, stage I AKI demonstrated 53% (10/19) mortality, stage II AKI demonstrated 67% (12/18) mortality, and stage III AKI demonstrated 68% (52/76) mortality (p < 0.001). We also noted that 50% (33/66) of patients with stage 0 AKI, 47% (9/19) of patients with stage I AKI, 22% (4/18) of patients with stage II AKI, and 18% (14/76) of patients with stage III AKI did not require RRT upon hospital discharge (p < 0.001). Among the patients that survived to discharge, there were no patients in stages 0 and I AKI that required RRT, however stages II and III AKI demonstrated 11% (2/18) and 13% (10/76) (p < 0.001) of patients required RRT upon hospital discharge. Conclusions: The degree of AKI should be considered as a prognostic indicator for patients on VA ECMO as the severity of AKI heralds important patient outcomes including mortality and the need for long-term RRT.