Kidney Replacement Therapies and Ultrafiltration in Cardiorenal Syndrome

Background: Some patients with cardiorenal syndrome 1 and congestion exhibit resistance to diuretics. This scenario complicates management and is associated with a worse prognosis. In some cases, rescue treatment may be considered by starting kidney replacement therapies or ultrafiltration. This decision is complex and necessitates a profound understanding of these techniques and the pathophysiology of this syndrome. These modalities are classified into continuous, intermittent, and ultrafiltration therapies, each with its own advantages and disadvantages that are pertinent in selecting the optimal treatment. Summary: In patients with diuretic-resistant cardiorenal syndrome, extracorporeal ultrafiltration and kidney replacement therapies have the potential to relieve congestion, restore the neurohormonal system, and improve quality of life. Key Messages: (i) In cardiorenal syndrome, the resistance to diuretics is common. (ii) Extracorporeal ultrafiltration and renal replacement therapies are rescue options that may improve the management of these patients. (iii) Better understanding of these modalities will help the development of new devices which are friendlier, safer, and more affordable for patients in these clinical settings.