Abstract 18625: Preemptive Continuous Renal Replacement Therapy in Pediatric Cardiac Patients Requiring Extracorporeal Support is Associated with Increased Mortality

Abstract

Objective: Acute kidney injury (AKI) is a common co-morbidity for children placed on ECMO because of primary cardiac disease; AKI can impact both length of ECMO support and adversely affect clinical outcomes. Continuous veno-venous hemofiltration (CVVH) is thought to optimize fluid status and lessen inflammatory response during pediatric ECMO support, leading some centers to use it as a standard adjunct to ECMO support. However, published data are derived primarily from the children without primary cardiac disease. Therefore, we reviewed our experience for pediatric cardiac patients receiving CVVH while on ECMO support. Methods: A retrospective analysis of the Children's Healthcare of Atlanta CICU ECMO database from 2002-2011 was performed. In order to limit the bias that CVVH would be instituted only after evidence of end-organ injury, we considered “pre-emptive CVVH” to be CVVH instituted with 48 hours of ECMO initiation. Multivariate logistic regression was undertaken to adjust for covariates. Results: Of 153 total cardiac ECMO patients, 59 (39%) received CVVH at the discretion of the attending physician. The time from ECMO initiation to CVVH initiation was 1.7 ± 2.9 days (median 1 day). Pre- and post-ECMO serum creatinine levels were similar between patients on ECMO who received CVVH with those that did not receive CVVH. However, peak serum creatinine was 1.1 ± 0.4 mg/dL (median 1.0 mg/dL) in the CVVH group and 0.9 ± 0.4 mg/dL (median 0.8 mg/dL) in the non CVVH group (p=0.003). Patients on ECMO who received CVVH had a higher mortality (p<0.0001), were less likely to have had ECPR (p=0.004), and had a longer duration on ECMO (p<0.0001). In multivariate analysis subjects receiving CVVH support within 48 hours of ECMO cannulation were three times more likely to die during their hospitalization (OR 3.02; 95% CI 1.32-6.9, p=0.009) even after adjusting for other risk factors such as ECPR, indication (post-operative support), and pre-ECMO serum creatinine. Conclusion: Preemptive CVVH support in pediatric cardiac patients requiring ECMO support is associated with increased in-hospital mortality. A strategy of pre-emptive CVVH in the cardiac ECMO population does not appear justified.