Effectiveness of minimal acute normovolemic hemodilution to minimize allogenic blood transfusion and re-exploration in elective adult coronary artery bypass graft surgery using colloid as a replacement solution

Background and aim Various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding, the need for allogenic transfusion, and the incidence of re-exploration in cardiac surgery. The aim of the present study was to evaluate the effectiveness of the use of minimal ANH for blood transfusion requirements and re-opening in elective adult coronary artery bypass graft surgery using cardiopulmonary bypass. Patients and methods This prospective, randomized controlled study was conducted on 100 consecutive adult patients who underwent elective coronary artery bypass graft. Patients were randomly divided into two equal groups: the ANH group (n=50) and the control group (n=50). In the ANH group, 5–8 ml/kg of autologous blood was withdrawn after administering anesthesia and before systemic heparinization. Simultaneously, colloid solution (6% hydroxyethyl starch 130/0.4; Voluven) was infused in a ratio of 1:1, and then the blood was re-infused after bypass. Hemodilation was not carried out for the control group. Total amount of allogenic-packed red blood cell, fresh frozen plasma, platelet concentrate transfusion, and the number of patients undergoing re-opening because of excessive bleeding were calculated for the two groups. Results A significant decrease was observed in the number of red blood cell units and fresh frozen plasma transfusion per patient in the ANH group compared with the control group. Conversely, chest tube output, representing postoperative bleeding and platelet count, did not differ between the two groups. Conclusion In this study, the use of the minimal ANH technique reduced the consumption of allogenic red blood cells and fresh frozen plasma in adult cardiac surgery patients. However, this technique had no effect on postoperative bleeding, incidence of re-exploration, and platelet count.