REDUCED BLOOD-LOSS AND TRANSFUSION REQUIREMENTS WITH LOW SYSTEMIC HEPARINIZATION - PRELIMINARY CLINICAL-RESULTS IN CORONARY-ARTERY REVASCULARIZATION

In coronary revascularization, low systemic heparinization was compared to full systemic heparinization during perfusion with heparin surface-coated cardiopulmonary bypass equipment. Twelve patients were randomly assigned to two groups and perfused with low [activated clotting time (ACT) > 180 s] or full (ACT > 480 s) systemic heparinization. A standard battery of blood samples was taken before the procedure, after heparinization, and at regular intervals during and after cardiopulmonary bypass. No differences were seen between the two groups in regard to age, body surface area, preoperative hematocrit, duration of bypass, bypass hypothermia, cross-clamp time, and number of bypasses per patient. However, there were more internal thoracic artery (ITA) grafts in the group with low systemic heparinization (1.5 +/- 0.8 ITA grafts per patient versus 0.8 +/- 0.4 ITA grafts per patient with full heparinization; p < 0.05). The oxygenator gradient at the end of perfusion (before weaning) was 107 +/- 80 mmHg for low versus 110 +/- 10 mmHg for full heparinization (difference not significant). The total amount of heparin used was 7200 +/- 1030 IU for low versus 51 400 +/- 9700 IU for full (p < 0.05). Postoperative hematocrit was 35.0 +/- 2.0% for low versus 24.7 +/- 2.7% for full (p < 0.05). Total chest tube drainage was 428 +/- 153 ml/m2 for low versus 935 +/- 414 ml/m2 for full (p < 0.05). Homologous transfusions of blood products were necessary in 3.6 patients for low versus 6/6 patients for full (p < 0.10). The total volume of packed red cells transfused was 221 +/- 228 ml/m2 for low versus 842 +/- 366 ml/m2 for full (p < 0.05). Final hematocrit at day 7 was 31.0 +/- 2.0% for low versus 33.0 +/- 3.0% for full (difference not significant). Full systemic heparinization can be avoided during clinical cardiopulmonary bypass by the use of heparin-coated perfusion equipment. A low dose of heparin , similar to the amounts given during vascular surgery, results in reduced blood loss and transfusion requirements.