BACKGROUND: Acute normovolemic hemodilution (ANH) entails collecting patients blood immediately before surgery with concurrent fluid infusion to maintain intravascular volume. This reduces the red cells mass (RCM) lost during surgery by lowering the hematocrit at which surgical blood loss occurs. Blood collected from ANH is transfused back to the patient at the end of surgery METHODS: 40 ASA I patients scheduled to elective surgery under lumbar epidural anesthesia were randomly divided into two groups, the ANH group where a pre-computed amount of blood was withdrawn just prior to induction of anesthesia with simultaneous infusion of equal amount of hydroxyethyl starch (HAES-STERIL) and the non-ANH group where no blood was withdrawn nor colloid infused. All patients were monitored based on the following parameters: mean arterial pressure, cardiac rate, central venous pressure, hematocrit, prothrombin activity, platelet count, arterial blood pH and hemoglobin oxygen saturation during the five phases of the study: before hemodilution, during hemodilution, surgery proper, immediate post-op and 24 hours after the surgery. Intraoperative blood loss was likewise monitored RESULTS: Comparative studies of the mean values were curried using one-way ANOVA with Complement Scheffes test and Paired T-test with a p value of 0.05 considered significant. The perioperative changes in the hemodynamic and hematologic parameters were not clinical significant CONCLUSION: The higher final hematotocrit level and the non-requirement for homologous transfusion in the hemodiluted group prove that ANH effective as a blood conservation technique. (Author)
Human ; Adult ; Young Adult ; Adolescent ; BLOOD TRANSFUSION ; HETASTARCH ; SURGERY ; ANESTHESIA