Backgrounds: In this study we aimed to compare the effects of acute normovolemic hemodilution on cardiac hemodynamia, tissue oxygenation, allogenic blood transfusion requirements and the amount of mediastinal drainage during the first postoperative day in patients undergoing coronary artery bypass graft surgery.

Methods: Thirtythree patients were randomly allocated into two groups. After induction of anesthesia, one or two units of blood was taken from the patients in the hemodilution group (G1, n = 16) until having a hemotocrit value of < 35%. At the same time, volume replacement was achieved with same amount of colloid infusion. Any additional procedure was not performed in the control group (G2, n = 17). Hemodynamic oxygenation and hematological parameters were measured before induction, after pulmonary catheter replacement, five minutes after removal of blood. In the control group, these parameters were measured 40 minutes after anesthesia induction, after protamine infusion and in the postoperative 6th hours and 24th hours.

Results: Hemotocrit 29-30% before pump, 18-20% with mild hypothermia during pump and 24-26% after pump and in the postoperative periods were found to be well tolerated. During hemodilution pulmonary and systemic vascular resistances decreased while cardiac index increased without an increase in heart rate. Tissue oxygenation was preserved in the early periods after hemodilution but increased lactate levels and decreased mixed venousoxygen saturation were detected in the postextubation period. These findings were more prominent in the control group. The allogenic blood transfusion requirements (31.5%) and the amount of mediastinal drainage (11.3%) were found to be higher in G2 when compared with G1 but this was not significant.

Conclusions: Acute normovolemic hemodilution can be used in coronary artery patients without any additional deterioration in hemodynamics and oxygenation, and acute normovolemic hemodilution can have positive effects on mediastinal drainage and allogenic blood transfusion requirements.

Keywords : Hemodilution, hemodynamia, tissue oxygenation, mediastinal drainage, blood transfusion