A continuous renal replacement therapy (CRRT) device that is completely worn on the body of a patient. A protocol is provided for installing the completely wearable CRRT device on a patient and changing or exchanging various CRRT device parts and fluids at predetermined intervals. A dialyzer or hemofilter is changed in a sterile environment while the dialysate and dialysate filters can be changed in a non-sterile environment by the patient.