COLLECTION OF AUTOLOGOUS BLOOD BEFORE ELECTIVE HIP-REPLACEMENT - A COMPARISON OF THE RESULTS WITH THE COLLECTION OF 2 AND 4 UNITS

The need for allogeneic blood can be reduced effectively with the use of preoperatively donated autologous blood. However, this collection a lso results in the waste of autologous blood in a considerable number of patients. In order to reduce overcollection, we requested that the amount of autologous blood donated before a total hip replacement be d ecreased from four units to two units. We then compared the amount of allogeneic blood required for fifty patients who had donated two units of autologous blood with that of fifty historical controls who had do nated four units. The patients were matched for sex, initial hemoglobi n concentration, and blood loss. There was no significant difference i n the percentage of autologous donors who received additional allogene ic blood; 20 per cent (ten) of the patients who had donated two units and 16 per cent (eight) of the patients who had donated four units req uired allogeneic blood (p = 0.12). Eighteen autologous units from the patients who had donated two units and fifty-one units from the patien ts who had donated four units were discarded. The erythropoietic respo nse, measured by the increase in the reticulocyte count, was comparabl e for the two groups. Iron stores, measured as the serum ferritin conc entration, were lower after the drawing of four units (33 +/- 39 micro grams per liter) compared with after the drawing of two units (49 +/- 29 micrograms per liter) (p = 0.03). The donation of two units of bloo d does not increase the exposure to allogeneic blood compared with the exposure after the donation of four units by patients who are going t o have a total hip replacement. The collection of two units rather tha n four helps to avoid the wasting of blood, decreases the costs and th e effort connected with the collection of blood, and preserves storage iron.