The optimal modality of renal replacement in critically ill patients with acute kidney injury remains a source of controversy. First year renal fellow Fahad Edrees, MD, tackled this important issue in his recent article entitled, “Prolonged Intermittent Renal Replacement Therapy,” published in Advances in Chronic Kidney Disease. With faculty coauthors Tingting Li, MD and Anitha Vijayan, MD, Edrees presents an up to date review of the increasingly popular form of renal replacement therapy that is neither intermittent hemodialysis nor is it a continuous therapy. Various terms are used to describe this inbetween therapy, including SLED, go-slow dialysis or extended daily dialysis but all are characterized by lower blood flows and longer sessions than with typical intermittent hemodialysis. Here at Washington University, the Division of Nephrology offers all modalities and all available machines in our ICUs. Fellows are thus well prepared to prescribe all possible renal replacement variations when they start practice.