老年患者全髋关节置换术前后事件相关电位变化的研究

目的：初步探讨老年患者全髋关节置换术前后事件相关电位（ERP）的变化。方法：选择无认知功能障碍临床症状、拟于全身麻醉下行全髋关节置换手术的老年患者30例，在手术前1d和手术后3d用ERP仪进行ERP的P300和N400刺激模式测定。手术前1d测得P3b（P300亚组成分）波幅下降低于3．0μV、潜伏期延长超过550ms的患者被设为阳性组，其余患者被设为阴性组。结果：阳性组患者术后P3b、N400潜伏期较术前明显延长，P3b、N400波幅及词条匹配率较术前明显降低（P均〈0．01）。阳性组患者手术前后各项指标与阴性组手术前后比较差异均有统计学意义（P均〈0．01）。结论：术前ERP的P3b波幅有下降和潜伏期延长的患者，术后认知障碍会进一步加重；ERP可能可作为老年患者全髋关节置换术后早期认知功能改变的量化指标.

Changes of event-related potentials before and after total hip replacement in elderly patients

Objective： To investigate the changes of event related potentials （ERP） in elderly patients before and after total hip replacement under general anesthesia. Methods： Thirty elderly patients with total hip arthroplasty received general anesthesia were included. ERP was detected preoperatively and 3 day after operation. Patients with preoperative P3b amplitude reduction by less than 3.0 μV and prolongation of latent period for more than 550 ms were assigned to positive group, while other patients were assigned to negative group. Results： On 3 day after surgery, the latent periods of P3b and N400 were significantly prolonged, while the amplitudes of P3b and N400 and vocabulary entries matching rate were significantly reduced in positive group （ P 〈 0.01 ）. Significant differences of all parameters between positive group and negative group were revealed preoperatively and postoperatively （P 〈0. 01 ）. Conclusion： The patients with declined cognitive activity preoperatively show further impairment postoperatively. ERP could be applied as predictive parameter in total hip replacement in elderly patients for cognitive impairment.