When to Start Kidney Replacement Therapy in Acute Kidney Injury: Framing the Controversy
The need to initiate KRT is unambiguous in patients presenting with life-threatening complications of AKI that are not readily correctable with medical measures. Such complications include severe acidemia, hyperkalemia, fluid overload and other uremic complications, such as bleeding. The clinical controversy, therefore, revolves around patients who have severe AKI but none of the aforementioned complications. Whereas some clinicians would advocate for the initiation of KRT preemptively, others support a philosophy of watchful waiting and reserving KRT for the management of complications. Observational studies highlight this controversy. In a sub-analysis of the Finnish Acute Kidney Injury study, patients who commenced KRT preemptively (i.e. with no evident conventional indications) had a lower 90-day mortality compared with patients who started KRT with a conventional indication. Conversely Libório et al. showed that KRT was associated with lower hospital mortality only among patients with AKI complications at the time of KRT initiation.
The rationale for earlier initiation of KRT is based on the notion that a preemptive strategy will provide a 'head start' in the control of fluid excess, the maintenance of electrolyte and acid--base homeostasis and the removal of uremic toxins. Although appealing in theory, the potential benefits of early KRT initiation should be weighed against the well described complications of acute KRT, such as iatrogenic hemodynamic instability, hypophosphatemia and the removal of crucial drugs (i.e. antibiotics) and nutrients. This is compounded by potential complications related to vascular access. such as bleeding at the time of insertion and catheter-associated bloodstream infections. Enthusiasm for a preemptive approach to KRT initiation is further dampened by the fact that even patients afflicted with severe AKI can experience recovery of their kidney function thus obviating the need for KRT had a conservative approach been taken.
Curr Opin Nephrol Hypertens. 2021;30(3):332-338. © 2021 Lippincott Williams & Wilkins