不同剂量氨甲环酸对体外循环心脏瓣膜置换术患者的血液保护效应

Blood-saving effect of different doses of tranexamic acid in patients undergoing cardiac valve replacement with cardiopulmonary bypass

目的 评价不同剂量氨甲环酸对体外循环心脏瓣膜置换术患者的血液保护效应.方法 择期行体外循环瓣膜置换术患者90例,性别不限,年龄18～60岁,体重指数16 ～ 25 kg/m^2,ASA分级Ⅰ-Ⅲ级.采用随机数字表法,将其分为3组（n=30）：对照组（C组）、大剂量氨甲环酸组（TL组）和小剂量氨甲环酸组（TS组）.麻醉诱导后30 min内TL组经静脉输注氨甲环酸20 mg/kg,然后以20mg· kg^-1 ·h^-1的速率持续输注至术毕;TS组经静脉输注氨甲环酸10 mg/kg,然后以10 mg· kg^-1·h^-1的速率持续输注至术毕;C组给予等容量生理盐水.于麻醉诱导前、术毕和术后24h时,采集中心静脉血样,测定Hb、Hct、Ph.于术后6和24 h时记录胸管引流量.记录术后24 h内异体红细胞的使用情况.记录住院期间死亡和相关并发症的发生情况.结果 与C组比较,TL组和TS组术后胸管引流量、异体红细胞的使用率和使用量降低（P＜0.05）,各时点Hb、Hct、Ph差异无统计学意义（P＞0.05）.TL组和TS组间上述指标比较差异无统计学意义（P＞0.05）.3组未见住院期间死亡和相关并发症的发生.结论 小剂量氨甲环酸适用于体外循环心脏瓣膜置换术患者的血液保护,即负荷量10 mg/kg、维持量10 mg·kg^-1·h^-1.

Objective To evaluate the blood-saving effect of different doses of tranexamic acid in patients undergoing cardiac valve replacement with cardiopulmonary bypass （CPB）.Methods Ninety ASA physical status l-Ⅲ patients,aged 18-60 yr,with body mass index of 16-25 kg/m2,scheduled for elective cardiac valve replacement with CPB,were equally and randomly divided into 3 groups using a random number table：control group （group C）,large-dose tranexamic acid group （group TL） and small-dose tranexamic acid group （group TS）.Anesthesia was induced with iv injection of midazolam,sufentanil and pipecuronium.The patients were endotracheally intubated and mechanically ventilated.Anesthesia was maintained with inhalation of isoflurane and iv injection of midazolam,sufentanil and pipecuronium.After induction of anesthesia,tranexamlc acid 20 mg/kg was intravenously infused over 30 min,followed by continuous infusion at 20 mg· kg^-1 · h^-1 until the end of operation in group TL,tranexamlc acid 10 mg/kg was intravenously infused over 30 min,followed by continuous infusion at 10 mg· kg^-1 · h^-1 until the end of operation in group TS,while the equal volume of normal saline was given instead in group C.Venous blood samples were taken before induction,at the end of operation and at 24 h after operation for determination of hemoglobin （Hb）,hematocrit （Hct）,and platelct count （Plt）.The volume of chest tube drainage was collected and recorded at 6 and 24 h after operation.The requirement for transfusion of allogeneic red blood cells was also recorded.The development of death and complications during days of hospitalization was recorded.Results Compared with group C,the volume of chest tube drainage was significantly decreased,the requirement for transfusion of allogeneic red blood cells was reduced （P 〈 0.05）,while no significant changes were found in Hb,Hct and Plt at each time point in TL and TS groups （P 〉 0.05）.There was no significant difference in the parameters mentioned above between group TL and group TS （P 〉 0.05）.The development of death and complications during days of hospitalization was not observed in the three groups.Conclusion Small-dose tranexamlc acid is suitable for blood-saving effect in patients undergoing cardiac valve replacement with CPB,that is loading dose of 10 mg/kg and maintenance dose of 10 mg· kg-1· h-1.