Does renal replacement therapy improve outcome? Controversies in acute kidney injury

All aspects of current treatment of acute kidney injury (AKI), including renal replacement therapy (RRT), are basically supportive. Emergent RRT is indicated in the management of AKI with refractory pulmonary edema, hyperkalemia or metabolic acidosis, or when uremic symptoms or signs develop. More aggressive practitioners use prophylactic RRT inpatients with sustained anuria, persistent oliguria with progressive azotemia and a probable glomerular filtration rate < 10 ml/min, or to prevent uncontrolled positive fluid balance in patients with AKI. However, this approach to RRT initiation in AKI is largely supported by retrospective analyses rather than prospective clinical trials. The approach to RRT dosing in AKI is more evidence-based. Outcomes in single-center studies of higher intensity versus standard RRT (intermittent and/or continuous) have been in consistent. However, two large multicenter negative randomized trials have shifted the weight of evidence towards suggesting provision of an effectively delivered standard dose of RRT in AKI, rather than seeking to increase RRT intensity.