Anaemia of Chronic Renal Failure

Abstract

Chronic anaemia is an almost invariable consequence of renal failure. As renal function deteriorates, there is a slow, progressive decrease in haemoglobin concentration that becomes particularly evident once the glomerular filtration rate (GFR) declines below 30 ml/minute (approximately corresponding to serum creatinine > 300 μmol/litre). This anaemia is important because it causes many debilitating symptoms (e.g. tiredness and lethargy, muscle fatigue, intolerance to cold, breathlessness on exertion, poor exercise capacity). It is also a major factor in the high prevalence of cardiovascular disease in renal patients, and their consequent increased morbidity and mortality; cardiovascular disease accounts for more than 50% of deaths in these patients. The anaemia of chronic renal failure (CRF) is normochromic and normocytic (unless superimposed iron deficiency is present), and hypoproliferative (because of reduced erythropoietic activity in the marrow). The reticulocyte count is therefore inappropriately low for the degree of anaemia, but the peripheral blood film often looks normal except for occasional fragmented RBCs ('burr cells', Figure 1). Blood volume studies show a reduced RBC mass, but normal total blood volume.