L-精氨酸对心内直视手术体外循环期间血小板的保护作用

The platelet protection of L-argiulne in open heart operation during cardiopulmonary bypass

目的探讨L-精氨酸对心内直视手术体外循环期间血小板的保护作用及临床意义。方法30例先天性房间隔缺损（ASD）、室间隔缺损（ASD）患者随机分为2组：L-精氨酸组（15例）于麻醉后切皮前将L-精氨酸200mg/kg加入5％葡萄糖注射液50ml中，经颈内静脉用微量注射泵以99ml／h的速度泵入体内；对照组（15例）同时以相同的速度泵入等量5％葡萄糖注射液，但未加任何药物。在麻醉后切皮前（基线值t1）、体外循环（CPB）后30min（t2）、CPB结束时（t3）、手术结束时（t4）、术后24h（t5）检测2组患者血小板数（PLT）、血小板膜表面糖蛋白CD62P阳性表达率的变化，并记录术后24h心包纵隔引流量；电镜观察血小扳形态及超微结构。结果切皮前2组患者一般资料比较差异均无统计学意义（均P〉0．05）。与t1相比，2组血小板数于t2-t4各时点均下降（均P〈0．05）；L-精氨酸组血小板数的下降幅度较对照组低（P〈0．05）。与t1相比，2组CD62P于t2-t4各时点均升高（均P〈0．05）；L-精氨酸组cD62P升高幅度较对照组低（P〈0．01），术后心包纵隔引流量较对照组明显减少（P〈0．05）。对照组血小板超微结构改变明显，L-精氨酸组血小板超微结构改变较对照组明显减轻。结论心内直视手术体外循环期间血小板超微结构、功能异常改变，易致术后出血；L-精氨酸在体外循环术中可以起到保护血小板、减少术后出血的作用。

Objective To discuss the platelet protective effect of L-arginlne in open heart operation during cardiopulmonary bypass （CPB）. Methods 30 cases of atrial septal defect （ASD） and ventricular septal defect （VSD） were divided randomly into L-arginine treatment group （n = 15） and control group（ n = 15）. In treatment group the patients received L-arginine 200 mg/kg which was added into 5% glucose solution{ GS） 50 ml through jugularis interna venous with microinfusion pump at 99 ml/h speed before cutting skin. In control group the patients received 5% GS 50 ml in which nothing was added. Blood samples were taken before cutting skin （ baseline t1 ） ,30 min after CPB started （ t2 ）, at the end of CPB （ t3 ）, at the end of operation （ t4 ）, and 24 h after operation （ t5 ） for determination of platelet counting （PLT） ,positive expression rate of platelet membrane glycoprotein CD62P. The volume of postoperative 24 h blood loss was recorded. The ultrastructural changes of platelets were observed by electron microscope. Results No significant differences were found of all the measurements before cutting skin. The platelet counting （PLT） was significantly declined at t2 ,t3 and t4 as compared with the baseline （t1） in both group（P 〈0. 05 ） ,but the decline was significantly larger in control group than in treatment group（P 〈0.05 ） ;the positive expression rates of platelets membrane glycoprotein CD62P were significantly increased at t2 ,t3 and t4 as compared with the baseline （t1） in both group（P 〈0.05） ,but the increase was significantly larger in control group than in treatment group （P 〈0.01 ）. There was significantly less postoperative 24h blood loss in the treatment group （P 〈 0.05 ）. The ultrastructural changes of platelets were significant in control group but significantly less changes of platelets in treatment group. Conclusion CPB results in platelet ultrastructural changes and decreased ,platelet function. L-arginlne is effective in preserving platelet during CPB,leading to less postoperative blood loss.