Intensity of renal replacement therapy and outcomes in critically ill patients with acute kidney injury: Critical appraisal of the dosing recommendations

The current care of critically ill patients with severe acute kidney injury requiring dialysis (AKI‐D) is limited to supportive management in which renal replacement therapy (RRT) plays a central role. Renal replacement techniques are invasive bioincompatible procedures and are therefore associated with complications that may prove harmful to fragile patients. Inexperience with the standards and lacking or misinterpreted recommendations for the delivery of the RRT dose increases the risk of serious complications. Neither the optimal doses of intermittent or continuous RRTs nor the minimal or maximal effective doses are known. The Kidney Disease Improving Global outcomes (KDIGO) AKI guidelines for RRT dosing recommendations are inflexible, based on limited research, and may be at least partially outdated. High‐intensity therapy may be associated with clinically relevant alterations in systemic and renal hemodynamics, profound electrolyte imbalances, the loss of nutrients or thermal energy, and underdosing of antimicrobial agents. However, higher doses of continuous renal replacement therapy (CRRT) may confer a survival benefit for certain subgroups of intensive care patients with severe AKI. Lower CRRT doses than the recommended adequate dosage may not lead to negative health outcomes, at least in Asian patients. Future research should evaluate the demand‐capacity concept, recognizing that the delivery of the RRT dose is dynamic and should be modified in response to patient‐related factors. There is a need for large‐scale studies evaluating whether precision RRT dose modifications may improve patient‐centered outcomes in subgroups of critically ill patients.