Hybrid therapies for supporting critically ill patients with acute kidney injury: when, how, and for whom?

Acute kidney injury (AKI) is common in critically ill patients. There is no specific pharmacological treatment for established severe AKI. Therefore, the conventional therapeutic strategy is limited to the use of kidney replacement therapy (KRT) to maintain homeostasis. Hybrid therapies optimize the advantages of intermittent and continuous modalities of KRT, combining lower hourly efficiency, longer application time, at lesser cost, but also adding different physicochemical principles of extracorporeal clearance. The sum of convection and diffusion, with or without adsorption or apheresis, and in different time combinations gives hybrid techniques great flexibility in prescribing a personalized treatment adapted to the needs of each patient at any given time. Hybrid therapies are increasingly being used due to their flexibility, which is determined by the combination of equipment, membranes, and available resources (machines and health-care personnel experience). The required technology is widely available in most intensive care units and uses low-cost consumables compared to other types of AKI treatment modalities, favoring its widespread use. Hybrid therapies are feasible and provide a viable form of KRT, either alone or as a transition therapy from continuous kidney replacement therapy to intermittent hemodialysis.