Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Cardiovascular Anesthesia
Introduction: Tetramethylpyrazine (TMPZ) is an active ingredient of a Chinese herbals medicine isolated from Ligusticum Chuanxiong previously found to have inhibitory effects on platelet function . Anti platelet activity of TMPZ included the inhibition of intracellular Ca++ mobilization, the enhancement of intracellular cAMP by inhibition of phosphodiesterase activity and the reduction of GP IIb/IIIa exposure on the surface of activated platelets . In this study, we examine the effects of TMPZ on platelet quantity and function during cardiopulmonary bypass.
Methods: With Institutional Ethics Committee approval and informed consents. Following 1 week of antiplatelet medication washout, fifteen patients underwent cardiac surgery that require cardiopulmonary bypass were divided into 2 groups. Group 1 (N=5) as control group. Group 2 (N=10) received TMPZ 8 mg/kg intravenously 15 minutes prior to CPB. Anesthesia was induced with amidate, fentanyl and vacuronium, and anesthesia was maintained with fentanyl and isoflurane in oxygen. After adequate heparinization, blood samples were obtained via radial arterial line at 5 minutes prior to CPB (base line value), 5 minutes, 15 minutes and 30 minutes into CPB for platelet count and platelet aggregation study. Data were analyzed using Student's t-tests with p<0.05 considered significant.
Results: The median age of patients was 34 yr. The median duration of CPB was 89 minutes. All patients tolerated procedure well. There were no significant hemodynamic changes during the observation. In Group 1, platelet count were significantly decreased by 50% (p<0.01) compare to base line value. In Group 2, platelet count were reduced to 83% of base line value and was significantly higher compare to the control group (p<0.01). During CPB, platelet aggregation was significantly reduced to 10% of base line value (p<0.01) in the control group. In group 2. during CPB, platelet aggregation maintain at 85% compared to that at pre pump. Post operative drainage were significantly less in group 2.
Conclusions: Previous studies shown inhibition of platelet aggregation activity of TMPZ. We conclude that TMPZ is clinically valuable in reducing post operative bleeding. TMPZ preserve platelet quantity and platelet function during CPB. Protection of platelet integrity and morphology might also be the mechanisms of TMPZ during CPB.
1. Chinese Med J1977;7:420-421.
2. Thromb Res 1994;75(1):51-62.