AGING AND COGNITION AFTER CARDIAC SURGERY

估计有30万患者将接受冠状动脉旁路移植术 1994年进行了冠状动脉旁路移植术。 越来越多的患者 老年人，我们刚刚发现，这一患者群体是 心脏病后特别容易出现早期认知功能障碍 手术 术后即刻神经心理功能障碍 月经周期是一个令人不安的临床问题，通常（在多达 83%的患者）手术成功。 我们将测试 低温保护大脑免受损伤的假设（如表现出的 在心脏手术期间改变认知功能）。 这是第一 亚低温对脑缺血再灌注损伤保护作用的前瞻性研究 冠心病术后神经心理功能障碍的发生率 动脉旁路手术（CABG）患者。 将有400名CABG患者 注册超过四年。 将通过随机化检验假设 年龄分层的患者为正常体温（36%C）和中度（28%C） 冠状动脉搭桥手术中的低温灌注。 体温过低会产生 脑代谢抑制和两者之间的程度 温度灌注改变脑氧代谢， 使用Xe 133清除率和动脉-颈静脉球静脉 计算脑氧代谢率的氧梯度 （CMRO2）。 调查的主要目的是确定 低温保护患者免于认知功能障碍。 的变化 在CMRO 2中，以及低温保护的时间将相关 随着一系列神经系统和 心理测验 认知功能的变化与 CPB期间CMRO 2和时间积分（体温过低）的降低。 一 调查的第二个目的是确定是否认知 功能障碍导致生活质量受损， 医院费用。 这将通过使用开发的一系列测试来完成 通过我们的调查人员来衡量生活质量， 分析程序也在这里开发，以检查医疗保健费用后， 心脏手术 这次调查中产生的新知识 立即适用于临床心脏手术。 结果可能 证明了维持认知功能的重要性， 生活质量和经济措施。 此外，信息将 扩大我们对低温保护作用的理解， 缺血性损伤

An estimated 300,00 patients will undergo coronary artery bypass graft (CABG) surgery in 1994. An increasing number of these patients are elderly, and we have just found that this patient population is particularly susceptible to early cognitive dysfunction after cardiac surgery. Neuropsychologic dysfunction in the immediate postoperative period is a disturbing clinical problem which often (in up to as many as 83% of patients) complicates successful surgery. We will test the hypothesis that hypothermia protects the brain from injury (as manifested in altered cognitive function) during cardiac surgery. This is the first prospective study of the protective effect of hypothermia on the postoperative incidence of neuropsychologic dysfunction in coronary artery bypass surgical (CABG) patients. 400 CABG patients will be enrolled over four years. The hypothesis will be tested by randomization of age stratified patients to normothermic (36%C) and moderate (28$C) hypothermic perfusion during CABG surgery. Hypothermia produces cerebral metabolic suppression and the degree to which the two temperature perfusions alter cerebral oxygen metabolism will be determined using Xe133 clearance and arterial - jugular bulb venous oxygen gradients to calculate the cerebral metabolic rate of oxygen (CMRO2). The primary aim of the investigation is to determine whether hypothermia protects the patient from cognitive dysfunction. The changes in CMRO2 as well as the time of hypothermic protection will be correlated with the changes in a serially administered battery of neurologic and psychometric tests. Change in cognitive function will be correlated with the reduction in CMRO2 and time integral (hypothermia) during CPB. A secondary aim of the investigation is to determine whether cognitive dysfunction leads to impairment in the quality of life and adds to hospital costs. This will be done by using a battery of tests developed by our investigators to measure quality of life and by a detailed cost analysis program also developed here to examine health care costs after cardiac surgery. New knowledge generated in this investigation will have immediate applicability to clinical cardiac surgery. The results may demonstrate the importance of maintaining cognitive function in terms of quality of life and economic measures. Furthermore, the information will expand our understanding of the protective effects of hypothermia against ischemic insult.