IMPACT OF PREOPERATIVE HEMODILUTION WITH ERYTHROCYTAPHERESIS ON HOMOLOGOUS BLOOD SAVING IN PATIENTS UNDERGOING TOTAL HIP-ARTHROPLASTY

Objectives: To compare three techniques for decreasing homologous bloo d requirements in total hip arthroplasty (THA), including preoperative autologous donation (PAD), preoperative acute normovolaemic haemodilu tion with erythrocytapheresis (erythro) and intraoperative normovolaem ic haemodilution (haemo). Study design: Prospective clinical trial. Pa tients: The study included 45 patients scheduled for THA, under genera l anaesthesia and operated on by the same surgeon. The patients were a llocated into three groups of 15 each. Methods: Blood loss was assesse d, during surgical procedure, by the weight of sponges and, the amount of blood collected in the suction bottles during and after surgery. T he haemoglobin concentration was measured al the time of preoperative assessement (d-30), just prior to surgery (d-1), in the recovery room (d+3h), and 1, 3, and 8 days later (d8). The transfusion end-point in the three groups was to obtain a haemoglobin concentration of 100 g . L-1 from d+3h until d8. Every pack of red blood cells transfused was w eighed and its haematocrit assessed to determine the accurate volume o f red blood cells. Results: In the three groups haemoglobin concentrat ion was similar from d+3h until d8. In the PAD group, no patient requi red homologous blood transfusion, There was no significant difference between the two other groups in the mean volume of homologous red bloo d cells required (308 +/- 197 mL in erythro group and 331 +/- 202 mL i n the haemo group, respectively). The intraoperative blood loss was si gnificantly higher (P = 0.001) in the erythro group: 914 +/- 305 mL vs 665 +/- 263 in the PAD group and 512 +/- 146 mL in the haemo group, r espectively. There was an inverse correlation between haematocrit at d -1 and intraoperative bleeding (r = -0.7) (P = 0.0001). The distributi on of the points was fitted as an exponential curve. Conclusions: In T HA, PAD is obviously the best technique to avoid homologous blood tran sfusion. However, when PAD is not feasible, removal of blood prior to surgery does not decrease requirements of homologous blood, as intraop erative blood loss is higher. Our results strongly question the use of major haemodilution during a surgical procedure exposing a major bloo d loss.