Recovery of renal function and survival after continuous renal replacement therapy during extracorporeal membrane oxygenation*

OBJECTIVE: To assess the outcome of pediatric patients supported by concomitant extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT). DESIGN, SETTING, AND PATIENTS: Acute kidney injury is associated with mortality in ECMO patients. CRRT in patients on ECMO provides an efficient and potentially beneficial method of acute kidney injury management. Concern that concomitant CRRT use increases the risk of developing anuria and chronic renal failure limits its use in some centers. We hypothesized that development of chronic renal failure is rare with concurrent ECMO and CRRT. We evaluated the outcomes of 154 ECMO/CRRT patients cared for over 10 yrs at a referral pediatric medical center. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 68 (44%) ECMO/CRRT survivors, 45 were assigned a pediatric risk, injury, failure, loss and end-stage (referred to as "pRIFLE") score at CRRT initiation. Seventeen (38%) patients met the criteria for Risk, 15 (33%) for Injury, and 10 (22%) for Failure. Two Failure patients later met End stage criteria. Of all survivors, 18 (26%) required ongoing renal replacement therapy (15 required continuous veno-venous hemofiltration, two required peritoneal dialysis, and one patient required intermittent hemodialysis) post ECMO discontinuation. Renal recovery occurred in 65 (96%) of 68 patients before discharge. One neonatal patient had sepsis-induced renal injury on transfer, but had normal creatinine 1 month later. Two pediatric patients with vasculitis and primary renal disease at presentation (both meeting Failure criteria) developed end-stage renal disease. One received peritoneal dialysis and subsequent renal transplant. The other has diminished function without need for renal replacement therapy. CONCLUSION: In the absence of primary renal disease, chronic renal failure did not occur after concurrent use of CRRT with ECMO. Concern for precipitating chronic renal failure by using CRRT during ECMO is not substantiated by this large single-center experience. Consistent with previous reports, mortality is higher in patients receiving concomitant CRRT and ECMO compared with those receiving ECMO alone. Mortality is similar to patients requiring CRRT who are not on ECMO. Additional studies are warranted to determine the optimal role of CRRT use in ECMO patients.