Preoperative autologous blood donation is one of the most widely used methods of autotransfusion. However securing a predetermined amount of blood (3 units of whole blood) may be difficult in patients with a low preoperative hematocrit. To determine the minimum effective pretreatment dosage of recombinant human erythropoietin required to secure an adequate amount of preoperative blood for autologous transfusion during
posterior decompression and instrumentation fusion using the pedicle screw-rod system in the lumbar spine, a prospective randomized clinical trial was done. Forty-five patients who had a preoperative hematocrit less than 40% were selected and were divided blindly into three groups. Fifty units per kilogram of recombinant human erythropoietin seems to be the minimal effective dosage for securing an adequate amount of preoperative autologous blood donation.