[Changes in blood volume during acute normovolemic hemodilution with 5% albumin or 6% hydroxyethylstarch and intraoperative retransfusion].

QUESTION: What is the impact of acute preoperative normovolemic hemodilution (ANH) on blood volume, intravascular colloid, and loss of red cells in the perioperative period?

METHODS

In 20 patients undergoing radical hysterectomy, preoperative ANH was performed to a hematocrit of 22% using 5% albumin (albumin group; n = 10) or 6% hydroxyethylstarch solution (HES group; n = 10). Intraoperative retransfusion of ANH blood was started at a hematocrit of 18%. Plasma volume (indocyanine green-dilution technique), hematocrit, and plasma protein concentration were measured before and after ANH, before retransfusion, and postoperatively. Red cell volume (labelling erythrocytes with fluorescein) was determined before and after ANH and postoperatively. In the HES group hydroxyethylstarch concentrations were measured in plasma and urine.

RESULTS

After removal of about 1,500 ml of blood and replacement with 15% more colloid solution, the blood volume was maintained in both groups after ANH. After a mean blood loss of about 1,800 ml, an average of 150 ml of red cells were saved due to ANH in both groups.

CONCLUSIONS

Double label measurements of blood volume demonstrated that with the colloids used a surplus of 15% of colloid infusion in relation to blood removal was necessary to generate isovolemia after ANH.