Management of early renal anaemia: diagnostic work-up, iron therapy, epoetin therapy

Effective management of early anaemia in the course of chronic renal insuff iciency requires the following: (i) implementing an efficient diagnostic st rategy to exclude common contributing factors; (ii) initiating epoetin ther apy for the majority of patients; and (iii) ensuring adequate iron supply f or erythropoiesis. Diagnostic inquiry is warranted whenever the haemoglobin concentration is b elow the normal range adjusted for age and gender. The most efficient diagn ostic approach is to assume erythropoietin deficiency, exclude iron deficie ncy, and pursue further diagnostic tests only when red-cell indices are abn ormal or when leukopenia or thrombocytopenia are also present. Macrocytosis should prompt an inquiry into alcoholism, B-12 deficiency, or folate defic iency. Microcytosis suggests iron deficiency or thalassaemia. Associated cy topenias raise the possibility of alcohol toxicity, pernicious anaemia, mal ignancy, or myelodysplastic syndrome. Epoetin therapy is warranted whenever the haemoglobin concentration has fallen below 10.0 g/dl. To initiate ther apy prior to dialysis, epoetin should be administered at an average dose of 100 IU/kg/week (80-120 IU/kg/week, 50-150 IU/kg/ week) by subcutaneous inj ection. Haemoglobin concentration should be monitored every 2 weeks and the epoetin dose adjusted by increments or decrements of 25% to maintain a rat e of rise of haemoglobin concentration of 0.2-0.6 g/dl (0.3-0.6 g/dl/week, 0.2-0.5 g/dl/week). When the target range is achieved, the dose of epoetin should be continually adjusted to maintain a stable haemoglobin concentrati on. Transferrin saturation and ferritin concentration should be monitored m onthly, and sufficient iron provided to maintain transferrin saturation abo ve 20%. The lower the haemoglobin concentration, the greater the likelihood that future intravenous iron will be required. Oral iron supplements shoul d be avoided, since they are costly, ineffective, and troublesome to patien ts. Finally, a blunted therapeutic response to epoetin therapy provides imp ortant diagnostic information and should prompt renewed diagnostic inquiry.