Reduction of blood utilization during myocardial revascularization.

The efficacy of four different blood conservation techniques in decreasing the homologous blood requirement in cardiac operations was studied prospectively in 100 patients undergoing myocardial revascularization. The patients were randomly assigned to four groups of 25 each as follows: group I, retransfusion of oxygenator blood after termination of extracorporeal circulation; group II, processing of oxygenator content by means of a cell separator; group III, predonation of autologous blood and isovolumetric substitution of hydroxyethyl starch (10 ml/kg bodyweight) after the induction of anesthesia in addition to the use of a cell separator; and group IV, predonation and the use of a cell separator plus postoperative retransfusion of shed mediastinal blood. To form homologous groups, we accepted only male patients without impairment of left ventricular function for the study. In addition, patients with internal mammary artery grafts and a duration of extracorporeal circulation less than 45 minutes or more than 90 minutes were excluded. The bank blood requirement during hospitalization was 2132 +/- 824 ml in group I, 1371 +/- 928 ml in group II, 833 +/- 599 ml in group III, and 408 +/- 559 ml in group IV. The use of blood conservation techniques resulted in reductions of homologous blood requirements of 34%, 60%, and 80%, respectively, in groups II to IV as compared with the requirement in group I. There were no complications related to autologous blood transfusion. We conclude that the use of blood conservation techniques can considerably reduce the homologous blood requirement in cardiac operations and therefore decrease transfusion-related risks.

[Reduction of whole blood requirements in coronary surgery with hemoseparation and isovolemic hemodilution]. / Reduzierung des Fremdblutverbrauchs in der Koronarchirurgie durch Hämoseparation und isovolämische Hämodilution.

Because of relative shortage of homologous stored blood, and the dangers of transmission infectious diseases and isoimmunisation, we tried to reduce blood requirement in cardiac surgery. In 139 patients undergoing coronary artery bypass surgery different techniques of autotransfusion were applied. A 52% reduction of whole blood transfusion compared to a control group of patients could be obtained by preoperative isovolaemic haemodilution. The application of haemoseparation reduced the amount of whole blood used by 55%. When the two techniques were combined the use of whole blood was reduced by 70% compared to the control group of patients. In contrast retransfusion of blood remaining in the oxygenator is not advisable because only a small amount of blood can be saved in this way and in addition it results in a higher risk of postoperative bleeding. Our results will be discussed reviewing the literature.