Complement and granulocyte activation were studied in cardiopulmonary bypass circuits completely coated with either end-attached covalent-bonded heparin, the Carmeda BioActive Surface, or with the Duraflo II bonded heparin, in combination with reduced systemic heparinization (activated clotting time > 250 seconds). The control groups were perfused with uncoated circuits and full heparin dose (activated clotting time > 480 seconds). Altogether 67 patients undergoing elective first-time myocardial revascularization were investigated, having extracorporeal perfusion with a Duraflo II coated circuit (n = 17), an identical but uncoated circuit (n = 17), a Carmeda coated circuit (n = 17), or an equivalent uncoated circuit (n = 16). During cardiopulmonary bypass, the C3 activation products C3b, iC3b, and C3c (C3bc) and the terminal SC5b-9 complemented complex increased markedly in all four groups compared with baseline, but significantly less in the two coated groups than in their control groups. Additionally, a significantly lower concentration of C3bc was observed in the Carmeda coated group, with maximal increase of median 28 AU/ml compared with 50 AU/ml in the Duraflo II coated group (p = 0.003). Similarly, in the Carmeda coated group, the maximal increase of terminal complement complex was considerably lower (0.8 AU/ml) than the levels recognized in the Duraflo II coated group (2.4 AU/ml) (p < 0.001). The release of the granulocyte activation myeloperoxidase and lactoferrin increased from the beginning of the operation, with peak levels at the end of bypass. A significant reduction of lactoferrin release was recognized when comparing the coated groups with the control groups. The difference between the two coated groups (Carmeda 228 micrograms/L; Duraflo II 332 micrograms/L; p = 0.05) was marginally significant. For myeloperoxidase, no significant differences were observed between the coated and uncoated groups. In conclusion, both types of heparin-coated circuits reduced complement activation and release of lactoferrin, but the Carmeda circuit proved to be more effective than the Duraflo II equipment.
Reduced systemic heparinization (ACT > 250 seconds) in patients having extracorporeal circulation with completely heparin-coated circuits did not lead to increased thrombogenicity. Thrombin formation remained within low ranges during CPB compared with patients receiving a full heparin dose and with the major elevations observed after surgery.
Because much interest has been focused on blood conservation using different drugs and complicated blood cell processing devices, we analyzed our results with the use of a non-pharmacologic, simple and inexpensive program for blood salvage in 2326 patients undergoing myocardial revascularization. The material was divided into two groups: patients undergoing a primary coronary bypass operation (Group P, n = 2298) and a smaller subset of patients undergoing repeat coronary bypass operation (Group R, n = 28). At least one internal mammary artery was grafted in 99% of the patients, with supplemental saphenous vein grafts. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of extracorporeal circulation. The volume remaining in the extracorporeal circuit was returned without cell processing or hemofiltration. Autotransfusion of the shed mediastinal blood was continued hourly up to 18 h after surgery in all patients. The mean postoperative mediastinal drainage in group R was 543 +/- 218 ml, compared to 703 +/- 340 ml in Group P (P = 0.01). In Group R, 1 patient (3.6%) received packed red cells and no patients were given other homologous blood products, compared to 33 patients (1.4%) given red cells and 35 patients (1.5%) given plasma transfusion in Group P (NS). Thus, in total, 2257 patients (97.0%) were not exposed to any homologous blood products during hospitalization. Total hemoglobin loss was significantly higher in Group R, resulting in a mean hemoglobin concentration at discharge of 109 +/- 13 g/l, compared to 121 +/- 14 g/l in Group P (P = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)
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