老年病人冠状动脉搭桥术后神经功能障碍的初步探讨

Neurological dysfunction after coronary artery bypass grafting in elderly patients

目的 通过对冠状动脉搭桥（CABG）术中进行经颅脑氧饱和度（TCCO）和经颅多谱勒（TCD）监测,探讨老年病人CABG术中局部脑氧饱和度（rSO2）和大脑中动脉微栓数量（HITS）的变化与术后神经功能障碍的关系。方法 择期CABG手术358例,根据年龄分为I组（年龄≥60岁）和Ⅱ组（年龄<60岁。术中使用TCCO和TCD持续监测rSO2和HITS,术后随访进行神经功能的检查和评估。结果 本组病人术后神经功能障碍发病率14％,其中I组为18.7％,Ⅱ组为6％,I组明显高于Ⅱ组（P<0.05）,同时I组的术后清醒时间、气管拔管时间、ICU时间、住院时间和住院死亡率也明显高于Ⅱ组。低 rSO2的发病率为25.4％,其中I组为30.2％,Ⅱ组为 17.3％,I组明显高于Ⅱ组（P<0.05）。而术中I组和Ⅱ组的HITS无明显差别（P>0.05）。结论 老年病人术后神经功能障碍发病率高,与术前合并脑血管病等危险因素和术中低rSO2发生率高有关,而与HITS的绝对数量无关。引起低rSO2的原因可能与低灌注、脑氧供/氧耗失衡、或低灌注和栓塞多种因素共同作用所致。

Objective To investigate the relationship between neurological complication after coronary artery bypass(CABG) and changes in regional cerebral oxygen saturation (rSO2) and the number of microemboli passing through right middle cerebral artery ( MCA) monitored by transcranial cerebral oximetry ( TCCO) and transcranial Doppler ultrasonography (TCD) during operation in elderly patients. Methods 358 NYHA class Ⅱ -Ⅲ patients undergoing primary elective CABG were divided into two age groups: group Ⅰ >60 yr ( n = 225) and group Ⅱ < 60 yr( n = 133) . In group I there were 141 males and 84 females, age ranged between 60-86 yr, 147 patients had associated hypertension, 54 diabetes and 21 cerebrovascular diseases . In group Ⅱ there were 92 males and 41 females, age ranged between 33-59yr, 77 patients had associated hypertension, 49 diabetes and 5 cerebrovascular diseases. TCCO sensor was placed on left forehead and rSO2 was continuously monitored. When value was lower than 80 % of baseline, it was considered to be low rSO2 .TCD detector was placed on right temple. MCA blood flow velocity and the number of microemboli passing through MCA( high-intensity transient signals, HITS) were recorded continuously. Results The overall incidence rate of neurological complications after CABG was 14% . It was 18.7% in group Ⅰ and 6.0% in group Ⅱ . The difference was significant between the two groups(P<0.05). The time of emergence from anesthesia, the extubation time, ICU stay and hospital stay were longer and mortality in hospital was higher in group Ⅰ than those in group Ⅱ ( P < 0.05 ) . The overall incidence rate of desaturation during operation was 25.4 % , it was 30.2 % in group Ⅰ and 17.3% in group Ⅱ?The difference was significant ( P < 0.05 ) . There was no significant difference in HITS between the two groups ( P > 0.05 ) . Conclusions The results suggest that the higher incidence of postoperative neurological complication in elderly patients is associated with higher rate of cerebral desaturation during operation and preoperative cerebrovascular diseases, but is not related to the number of microemboli passing through MCA during CABG.