During artificial organ support, kidney injury is multifactorial and related to the high severity of patients treated with extracorporeal membrane oxygenation (ECMO). The successful delivery of continuous renal replacement therapy (CRRT) during ECMO requires a clear prescription of the target solute clearance and fluid removal rate based on the cumulative fluid balance and physiological variables. The role of CRRT and the optimal time, modality, and dose still need clarification.