中低温体外循环期间脑氧代谢的变化  

Cerebral oxygenation during moderate and low in vitro circulation for cardiopulmonary bypass in cardiac valve replacing operation

作　　者：黄燕红[1] 徐明清[1] 万震威[1] 张伟平[1] 

机构地区：[1]韶关粤北人民医院麻醉科,广东韶关512026

出　　处：《中国热带医学》2006年第6期1087-1088,共2页China Tropical Medicine

摘　　要：目的观察中低温体外循环中瓣膜置换患者的脑氧代谢及脑糖、脑乳酸的变化. 方法择期行瓣膜置换25例,ASA Ⅱ～Ⅲ级,行颈内静脉逆行置管至颈内静脉球部,分别于CPB前（T1）、转流后鼻咽温降至35℃（T2）、32℃稳定10min（T3）、复测温至35℃（T4）、停机后30min（T5）采取颈内静脉球部血及桡动脉血进行血气分析,测定血糖及乳酸,并计算脑氧摄取率（O2 Ext）、脑动静脉血糖差（Ga-j）以及乳酸差（AVDL）. 结果 CPB开始后,患者动脉血氧含量、动-颈内静脉血氧含量差和脑氧摄取率迅速下降（P＜0.05）,随着复温又迅速升高.动脉和颈内静脉乳酸含量呈进行性增高,但各时间点的动-颈内静脉血的乳酸浓度差无明显变化（P＞0.05）.停CPB时,患者动-颈内静脉血氧含量差仍明显低于转流前水平（P＜0.01）. 结论中低温麻醉下的体外循环,可满足CPB过程中的脑氧供需平衡.CPB结束后,脑氧代谢可能会继续升高,是否发生脑氧供需失衡值得进一步研究.Objective To observe the changes of metabolism of cerebral oxygen, glucose and lactate during moderate and hypothermic cardiopulmonary bypass （CPB） in cardiac valve replacement surgery. Methods Twenty five patients scheduled for cardiac valve replacement with CPB were selected. The data concerning the contents of oxygen, glucose and lactate were recorded before CPB, at pharynx temperature of 35 ℃ during cooling, The temperature was kept at 32 ℃ for 10 minutes and heated to 35 ℃ 30 minutes after CPB. Cerebral oxygen extraction （02 Ext） and glucose differences between arterial and jugular bulb blood （Ga- j）, lactate differences between arterial and jugular bulb blood （AVDL） were calculated. Results Arterial - venous difference and oxygen uptake rates were both decreased after the commencement of CPB, and were rapidly increased during heating.The concentration of lactic acid in plasma was progressively increased during CPB. AVDL did not vary significantly. Arterial - venous difference in the oxygen content was still lower during CPB than that before CPB. Conclusion Moderate and hypothermia anesthesia during CPB can maintain the balance of cerebral oxygen metabolism. Cerebral oxygenation will progressively increase after CPB under hypethermia, but whether imbalance of celebral oxygen metabolism will occur remain to be investigated.

关 键 词：瓣膜置换 低温 体外循环 脑氧代谢 

分 类 号：R331[医药卫生—人体生理学]