体外循环心瓣膜置换术中止血环酸的应用

目的　体外循环心瓣膜置换术中应用止血环酸（ｔｒａｎｅｘａｍ ｉｃ ａｃｉｄ），观察其对血小板的保护作用。　方法５０ 例心瓣膜置换术的患者随机分为止血环酸组和对照组，用双盲法进行实验。止血环酸组术前静脉注射止血环酸１０ｍ ｇ／ｋｇ，预充液中加５ｍ ｇ／ｋｇ（总量累计超过１ｇ 者，按１ｇ 计算，２／３ ｇ 静脉注射，１／３ ｇ 加入预充液中）；对照组分别加等量生理盐水。测定两组转流前、后血小板粘附率、血小板聚集率、血小板计数，观察术后 ２４ 小时出血量和输血量。结果　转流后两组血小板功能均有下降，但对照组明显低于止血环酸组（ Ｐ＜ ００５）；转流后止血环酸组血小板计数无明显变化（ Ｐ＞ ００５）；转流后对照组血小板计数明显低于转流前（ Ｐ＜ ００１），且明显低于止血环酸组（ Ｐ＜ ００５）；出血量和输血量止血环酸组均低于对照组（ Ｐ＜ ００５）。　结论　止血环酸能有效保护血小板，明显减少术后出血及输血量。

The Use of Tranexamic Acid in Heart Valve Replacement with Extracorporeal Circulation

Objective To assess the effect of tranexamic acid on platelet during heart valve replacement with extracorporeal circulation. Methods Fifty patients were randomly divided into two groups(25 patients per group).The tranexamic acid group received tranexamic acid (total dose 15mg/kg) before extracorporeal circulation; the control group received a placebo saline of equal volume. Blood samples were collected before and after extracorporeal circulation to assess platelet adhesiveness, aggregation, platelet count. Results Preoperatively, platelet functions and count were similar in two groups. Postoperatively,platelet functions decreased in both groups, but platelet functions in control group were lower significantly than that in tranexamic acid group ( P <0 05); platelet count decreased significantly in control group( P <0 01) but no change in tranexamic acid group. Total postoperative 24 hours bleeding and blood requirement were lower in the tranexamic acid group( P <0 05). Conclusion The results suggest that the use of tranexamic acid in heart valve replacement with extracorporeal circulation reduces postoperative bleeding,blood requirement and protect platelet.