Etiology and Prevention of brain function disorder often cordiovascular surgery

通过查阅以往关于心脏和主动脉手术后脑功能障碍的发生率和临床特点的报道，我们分析了与心血管手术相关的脑损伤的病因和预防措施。据报道，心脏手术后卒中的发生率为1%-5%，而包括认知功能在内的脑功能障碍的发生率为30%-80%。栓塞事件、脑血流改变、全脑灌注不足、脑再灌注损伤和cpb引发的全身炎症反应是可能的机制。在潮末CO_2压（P_<ET>CO_2）、肺动脉压（PAP）和经食管二维心电图（TEE）监测下，评价体外循环结束时清除残留空气的新方法。逐渐提高体外循环的贮液量，减少静脉引流。因此，右心脏开始接收更多的静脉血并将其排出肺动脉。存在于左心室或左心房的通风口收集了所有来自肺循环的含有气泡的全血。经TEE确认气泡已被清除，未从左心室射入体循环。P_<ET>CO_2在抽气过程中达到28±4 mmHg， PaCO_2同时达到35±6 mmHg （P<0.05）。抽气时间为9±2 min。P_<ET>CO_2和PAP是肺循环的有用指标。P_<ET>CO_2为25-30 mmHg， PAP为预旁路水平的90%是去除空气所必需的。建议我们采用P_<ET>CO_2， PAP和TEE去除空气的技术能够令人满意地消除残余空气。然而，这些方法不能显著降低心脏手术后脑功能障碍的发生率。由此，我们得出结论，CPB期间动脉粥样硬化和脂肪栓塞以及脑血流量减少可能是心脏手术期间和之后脑损伤发生的重要原因。少

By searching previous reports concerning the incidence and clinical characteristics of brain function disorder following cardiac and aortic surgeries, we examined to analyze the etiology and preventative measure in brain damage in association with cardiovascular surgery. The incidence of stroke is reported to be 1%-5% after cardiac surgery, whereas that of brain function disorder including cognitive function is 30%-80%. Embolic events, changes in cerebral blood flow, global hypoperfusion, cerebral reperfusion injury, and CPB-triggered whole body inflammatory response represent possible mechanisms. We evaluated our new method for removal of retained air at the termination of cardiopulmonary bypass under the monitoring of end-tidal CO_2 pressure (P_<ET>CO_2), pulmonary arterial pressure (PAP) and transesophageal two-dimensional cardiography (TEE). The Reservoir of the cardiopulmonary bypass was gradually raised to decrease the venous drainage. Accordingly, the right heart began to receiv … More e the venous blood and eject it to the pulmonary artery. The vent existing in the left ventricle or the left atrium then collected any whole blood containing air bubbles that came from the pulmonary circulation. The air bubbles were confirmed to be removed and not to eject from the left ventricle to the systemic circulation by TEE. P_<ET>CO_2 reached 28 ± 4 mmHg during the removal of air, whereas the simultaneous PaCO_2 of 35 ± 6 mmHg (P<0.05). The duration time of removal of air was 9 ± 2 min. The P_<ET>CO_2 and PAP are useful indicators of pulmonary circulation during our procedure for removal of air. P_<ET>CO_2 of 25-30 mmHg and PAP of 90% of the prebypass level have been found to be necessary for the removal of air. It is suggested that our technique for removal of air using P_<ET>CO_2, PAP and TEE enables us to satisfactorily eliminate residual air. However, these methods could not significantly decrease the incidence of brain function disorder following cardiac surgery. From these, We conclude that atherosclerotic and fat embolisms and a decrease in cerebral blood flow during CPB may be important for genesis of brain damage during and after cardiac surgery. Less