The present invention concerns a multipart fluid system for use in CRRT, wherein the multipart fluid system comprises an anticoagulation fluid and at least one fluid from the group consisting of a dialysis fluid and an infusion fluid. According to the invention the anticoagulation fluid comprises at least 8 mM citrate, and the dialysis fluid and/or infusion fluid comprises 2-8 mM citrate and 1-5 mM total calcium. The present invention further concerns a system for regional citrate anticoagulation in an extracorporeal blood circuit.
