The selective cytopheretic device (SCD) is comprised of tubing, connectors and a hemofilter cartridge. The device is connected in series to commercially available Continuous Renal Replacement Therapy (CRRT) devices. Blood from the CRRT circuit is diverted after the CRRT hemofilter through to the extra capillary space (ECS) of the SCD. Blood circulates through this space and it is returned to the patient via the venous return line of the CRRT circuit. Regional citrate anticoagulation is used for the entire CRRT and SCD blood circuits.