全麻术中过度通气对老年腹腔镜手术患者脑乳酸代谢的影响  

Effect of Hyperventilation on Cerebral Lactate Metabolism of the Elderly Undergoing Laparoscopic Operation under General Anesthesia

作　　者：张瑜[1] 冯鹏程 王兵兵 裴晓娟[1] Zhang Yu;Feng Pengcheng;Wang Bingbing;Pei Xiaojuan(Department of Operation and Anesthesia, the Second Affiliated Hospital to Shaanxi University of Traditional Chinese Medicine, Xianyang City, Shaanxi Province, 712000, P. R. China)

机构地区：[1]陕西中医药大学第二附属医院手麻科,陕西咸阳712000

出　　处：《老年医学与保健》2018年第6期690-693,共4页Geriatrics & Health Care

摘　　要：目的探讨静脉麻醉中过度通气对老年腹腔镜患者脑乳酸代谢的影响,并分析其降低脑血流量的相关机制。方法选取2016年1月—2017年1月我院普外科收治的40例腹腔镜手术的老年患者为研究对象,所选患者均行全身静脉麻醉,气管插管呼吸机A/C模式辅助通气,实时监测呼气末动脉血二氧化碳分压。手术前分别在30 mmHg<呼气末动脉血二氧化碳分压≤35 mmHg和35 mmHg <呼气末动脉血二氧化碳分压≤40 mmHg时测定血流动力学以及脑乳酸代谢相关指标,如脑血流量、脑动脉血流速度和乳酸代谢率等。其中脑血流量测定采用改良K ty-Schmidt技术,以氩气为惰性气体示踪剂。结果过度通气状态显著减少大脑血流量、血流速度、大脑氧供应及颈静脉球氧气分压,而脑氧气和葡萄糖代谢率保持不变。然而,脑乳酸净流出量显著增加。结论过度通气会导致经静脉麻醉的腹腔镜老年患者的脑乳酸净流出量显著增加,脑血流量和颈静脉球的氧分压明显减少,提示低碳酸血症可能会损害脑有氧代谢水平。Objective To discuss the effect of hyperventilation in intravenous anesthesia on cerebral lactate metabolism of the elderly undergoing laparoscopic operation and the mechanism of reducing cerebral blood flow.Methods40elderly cases undergoing laparoscopic operation during the period fromJan.,2016 to Jan.,2017 were selected;general intravenous anesthesia and tracheal intubation with the ventilator in assist/control mode were performed;real-time monitoring was made to partial pressure of carbon dioxide in end expiration(PETCO2);related index of The hemodynamics and lactate metabolism,including the blood flow of the brain,the velocity of cerebral artery blood flow and the metabolic rate of lactic acid,were measured before operation at the time point when carbon dioxide partial pressure in end expiration was less than 30mmHg,less than 35 mmHg and less than40mmHg;modified K ty-Schmidt technique,taking argon as an inert gas tracer,was applied in measuring the cerebral blood flow.Results Hyperventilation significantly reduced the volume and speed of cerebral blood flow,cerebral oxygen supply and the oxygen partial pressure of the jugular bulb while the metabolic rate of brain oxygen and glucose remained unchanged;the net flow of brain lactic acid increased significantly.Conclusions Hyperventilation can lead to a significant increase in the net flow of brain lactate of the elderly undergoing intravenous anesthesia and a significant decrease in the cerebral blood flow and the oxygen partial pressure of the jugular bulb,which suggests that hypocapnia may damage the level of brain aerobic metabolism.

关 键 词：老年 腹腔镜手术 静脉麻醉 过度通气 乳酸 

分 类 号：R614[医药卫生—麻醉学]