Perioperative use of erythropoietin

Erythropoietin (EPO) is the primary regulator of red blood cell (RBC) production, and hypoxia is the main stimulus for EPO secretion. Increases in circulating levels of EPO are proportionate to the levels of tissue hypoxia, which are influenced by hematocrit (HCT). Small decreases in HCT as would be typical after presurgical autologous blood donation often do not result in increased EPO levels or in compensatory erythropoiesis. Erythropoiesis may also be limited by deficiencies of vitamin B(12), folate, and, most commonly, iron. The preoperative administration of EPO is effective in increasing erythrocyte mass and autologous donation volumes while maintaining higher HCT levels. In some surgical populations, particularly those individuals who experience surgical blood losses in excess of 2 L, EPO treatment also reduces allogeneic blood exposure. This effect is prominent in patients with a low initial HCT. Current assessments of the cost-effectiveness of EPO suggest that it achieves little overall improvement in patient health and that what improvement it does offer, it does at enormous cost.