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Reduction of heparin dose is not beneficial to platelet function
T Nakajima1, K Kawazoe, K Ishibashi
1Third Department of Surgery, Iwate Medical University School of Medicine, Japan. t_nakajima@imu.ncvc.go.jp
Insights
Reducing heparin dose during cardiopulmonary bypass with heparin-coated circuits preserves platelets and lowers leukocyte adhesion. This strategy minimizes platelet loss without affecting platelet activation markers.
Area of Science:
- Cardiovascular Surgery
- Hematology
- Biomaterials Science
Background:
- Cardiopulmonary bypass (CPB) can lead to platelet loss and activation.
- Heparin is crucial for anticoagulation during CPB but can affect platelet function.
- Optimizing heparin dosage while maintaining safety is essential.
Purpose of the Study:
- To investigate the impact of reduced heparin dosage on platelet counts and activation during CPB.
- To evaluate the effect of lower heparin doses on leukocyte adhesion to CPB equipment.
- To assess the efficacy of heparin-coated circuits in conjunction with reduced heparin administration.
Main Methods:
- Prospective trial involving 23 patients undergoing coronary artery bypass grafting.
- Comparison of two groups: standard heparin dose (300 IU/kg) versus reduced dose (200 IU/kg).
- Utilized heparin-coated CPB equipment for all participants; measured platelet counts, beta-thromboglobulin (beta-TG), and platelet factor 4 (PF4); analyzed arterial filters via electron microscopy.
Main Results:
- Higher platelet counts observed in the low-dose heparin group (p < 0.01).
- No significant differences in beta-thromboglobulin and PF4 concentrations, indicating unchanged platelet release reaction.
- Markedly reduced cell adhesion, primarily neutrophils, on arterial filters in the low-dose group (p < 0.01).
Conclusions:
- Reduced heparin dosage, when combined with heparin-coated CPB equipment, effectively minimizes platelet loss.
- The reduction in heparin dose does not suppress the platelet release reaction.
- Lowering heparin administration decreases leukocyte adherence to the CPB filter surface, potentially reducing inflammatory responses.
Background:
To clarify the effects of the reduction of heparin dose on platelets, we conducted a prospective trial on patients undergoing cardiopulmonary bypass.
Methods:
Twenty-three patients undergoing coronary artery bypass grafting were studied. The systemic heparin dose was 300 IU/kg in the control group (n = 11) and 200 IU/kg in the low-dose group (n = 12). Heparin-coated cardiopulmonary bypass equipment was used for both the groups. Platelet counts, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) concentrations were measured and the arterial filters in the circuits were observed by electron microscopy.
Results:
Platelet counts were higher in the low-dose group than in the control group (p < 0.01). No significant differences were found in the platelet release reaction (beta-TG and PF4). Electron microscopy demonstrated that cell adhesion on the arterial filters in the control group was significantly more marked than in the low-dose group (p < 0.01) and that most of the cells on the filters were neutrophils.
Conclusions:
We conclude that the reduction of heparin dose with the use of heparin-coated equipment reduces platelet loss, but does not suppress the platelet release reaction. Furthermore, the reduction of heparin dose reduces adherence of leukocytes to the filter surface.