体外循环期间钙动态变化的研究

观察32例患者体外循环期间血浆及红细胞内钙的动态变化。目的在于揭示其变化规律，为更好的保护心肌提供新的措施和理论依据。结果：麻醉后体外循环前血浆钙较术前显著升高，体外循环开始显著下降；40min恢复至术前水平；停机时显著升高至停机8h。术前、中、后红细胞内钙无显著变化。体外循环期间钙变化与血液稀释、应激反应、预充液及心脏停跳液中含钙离子有关。高钙可导致心肌缺血及再灌注时大量钙进入心肌细胞，引起心肌细胞损伤。所以，体外循环期间，特别是复灌期适当降低钙浓度，对术中、后心肌功能恢复具有重要作用。

THE STUDY ON THE CHANGES OF CALCIUM DURING CARDIOPULMONARY BYPASS

32 patients during cardiopulmonary bypass(CPB) were observed for their variations of calcium concentration in plasma and erythrocytes.The purpose of this study is to reveal changes of cal-cium during CPB, and to supply new measures and theoretical basis for myocardial preservation effec-tively. The results indicated that calcium in plasmaincreased significantly at pre-CPB and decreased sig-nificantly at the beginning of CPB, and returned topreoperative calcium concentration at 40 minutes af-ter beginning of CPB, and increased significantlyfrom ending CPB to 8 hours after operation. Calci-um in erythrocytes did not change significantly be-fore, during and after open-heart surgery. The vari-ations of calcium during CPB have relations tohemodilution, stress, and calcium concentration in priming solution and cardioplegic solution. Hyper-calcemia is easy to lead to myocardial ischemia and myocardial cell injury by much ionized calcium mov-ing myocardial cell in reperfusion. So calcium con-centration decreased appropriately in plasma during CPB and reperfusion plays an important role in re-ducing myocardial ischemia and reperfusion injury,and recovering myocardial function during and after operation-