The effect of acute normovolemic hemodilution and acute hypervolemic hemodilution on coagulation and allogeneic transfusion

Objective: In this study, acute normovolemic hemodilution (ANH) and hypervolemic hemodilution (HHD) were compared with no hemodilution with regards to the effectiveness in blood usage and coagulation parameters. Methods: The study was performed from February to August 2001 at Hacettepe University Hospital, Ankara, Turkey. Thirty patients undergoing hip arthroplasty surgery were prospectively randomized into: ANH group [autologous blood 15 mL kg(-1) was withdrawn and replaced by 6% hydroxyethyl starch (HES)] or HHD group (HES was administered without removal of any autologous blood) or the control group (no hemodilution). In all groups, blood was given when hemoglobin concentration was <9 g dl(-1). Results: Three groups were clinically similar regarding blood loss, mean arterial pressures and coagulation parameters. But allogeneic transfusion requirements were significantly less in hemodilution groups (20% in ANH, 40% in HHD) compared to the control group (100% of patients). Conclusion: We conclude that hemodilution (both ANH and HHD) decreases the demand for homologous blood without adversely affecting hemodynamics or coagulation parameters and HHD seems to be a simple and valuable alternative to ANH in orthopedic patient undergoing hip replacement.