What is dialysis, and why are the patients at risk for anemia?

Cleansing of blood: Dialysis is the cleansing of the blood through an artificial membrane. It replaces some of the physiologic functions of a normal kidney but is generally inferior to a functioning kidney. One of the functions of the kidney is to produce a hormone that stimulates blood produciton. When kidney function is impaired, this hormone production is diminished, resulting in anemia.

CrCl < 50 ml/min: When a patient's renal function (creatinine clearance (crcl)) drops below the level of 50ml/min (normal is ~140ml/min), patients can become anemic. This is because at that level, the relative production of erythropoetin is impaired. If anemia develops, and the iron stores are replete, EPO or Aranesp (darbepoetin alfa) can be given to increase EPO level stimulation of the bone marrow to make red cells.