Renal replacement therapy in critically ill patients: who, when, why, and how

Purpose of review The increasing incidence of acute kidney injury has the immediate effect of a growing need for renal replacement therapy (RRT). Shedding light on the questions of who, when, why, and how RRT should be performed is difficult to accomplish because of ambiguous study results, poor quality evidence, and low standardization. Recent findings Critically ill patients are exposed to multiple factors known to deteriorate kidney function. Especially severe fluid overload is strongly associated with worse outcome and may be considered as a trigger for initiating RRT. In the absence of life-threatening complications, a strategy of early initiation of RRT might be most advantageous keeping in mind the potential adverse effects of RRT. By providing better hemodynamic stability and superior control of fluid balance continuous RRT is the first choice therapeutic tool as compared with intermittent techniques. The femoral and jugular veins are the preferred insertion sites for temporary catheters. Although data are still weak, there is some preliminary evidence that regional citrate anticoagulation is superior to systemic heparinization. Summary The best management of RRT is still a subject of controversy. Continuous RRT with regional citrate anticoagulation via a temporary catheter in a jugular vein is the recommended first choice treatment option in critically ill patients with acute kidney injury.