Changes in intravascular volume during acute normovolemic hemodilution andintraoperative retransfusion in patients with radical hysterectomy

Background: Changes in blood volume during acute normovolemic hemodilution (ANH) and their consequences for the perioperative period have not been inv estigated sufficiently. Methods: in 15 patients undergoing radical hysterectomy, preoperative ANH t o a hematocrit of 24% was performed using 5% albumin solution. Intraoperati vely, saline 0.9% solution was used for volume substitution, and intraopera tive retransfusion was started at a hematocrit of 20%, plasma volume (indoc yanine green dilution technique), hematocrit, and plasma protein concentrat ion were measured before and after ANH, before retransfusion, and postopera tively, Red cell volume (labeling erythrocytes with fluorescein) was determ ined before and after ANH and postoperatively, Results: Mean. normal plasma volumes (1,514 +/- 143 ml/m(2)) and reduced re d cell volumes (707 +/- 79 ml/m(2)) were measured preoperatively. Blood (1, 150 +/- 196 ml) was removed and replaced with 1,333 +/- 204 ml of colloid. Blood volume before and after ANH was equal and amounted to 3,740 ml, Intra operatively, plasma volume did not increase until retransfusion despite inf using 3,389 +/- 1,021 ml of crystalloid (corrected for urine output) to com pensate for an estimated surgical blood loss of 727 +/- 726 ml, Postoperati vely, after retransfusion of all autologous blood, blood volume was 255 +/- 424 ml higher than preoperatively before ANH. Despite mean calculated bloo d loss of 1,256 +/- 892 mt, only one patient received allogeneic blood. Conclusions: During ANH, normovolemia was exactly maintained. After surgica l blood loss of 1,256 +/- 892 ml crystalloid and colloid supplies of 5,752 +/- 1,462 ml and 1,667 +/- 548 ml, respectively, and complete intraoperativ e retransfusions of autologous blood in every patient, mean blood volume wa s 250 ml higher than preoperatively before ANH.