颈动脉狭窄手术安全预警与优化策略研究

【作者】 马博；

【导师】 刘昌伟； 刘暴；

【作者基本信息】 北京协和医学院 ， 临床医学， 2013， 博士

【摘要】 目的通过对颈内动脉内膜剥脱术患者临床资料的统计分析,探究术中低灌注的危险因素,发现有意义的预警指标并探索相应的优化策略,以期降低围手术期并发症的发生率,改善患者预后。通过建立返搏压／系统血压指数,评价术中血压波动对返搏压诊断术中缺血的准确性的影响。方法本研究为前瞻性观察性临床研究,从2009年至2012年共176例全麻情况下颈动脉内膜剥脱术病例被纳入本研究。根据患者的临床资料和围手术期监测结果进行分析,其中围手术期监测手段主要是TCD、系统血压和返搏压的测量。利用线性回归的方法分析了返搏压与大脑中动脉血流速度之间的关系。以术中TCD监测的阻断后大脑中动脉血流速度下降大于等于50%为术中低灌注的判断标准,比较了返搏压与返搏压指数监测术中低灌注的敏感性和特异性。利用Logistic回归分析等统计学方法分析了患者发生术中低灌注的危险因素。结果1.根据75例具有返搏压病例的数据显示返搏压和阻断颈内动脉后大脑中动脉血流速度之间无明显的线性关系(r2=0.201,p<0.001),而返搏压与阻断前后血流速度百分比之间也无明显的线性关系(r2=0.180,p<0.001)。2.阻断后大脑中动脉血流速度降为0的患者有15例,其术后发生TIA的风险较其他患者大。而阻断后大脑中动脉血流速度较阻断前增加的患者有14例,在我们的研究中,此类患者的术后风险并未增加。但是他人的研究认为相对于其他患者,该类患者仍可能有较大的术后风险。3.返搏压指数与返搏压的ROC曲线下面积都在0.7以上,这说明这两种监测指标对监测术中低灌注都具有一定的准确性。两者的准确性并不明显区别,这表明术中系统血压波动对返搏压监测的准确性无明显影响,阻断颈动脉后的血压调节过程不会影响返搏压的使用。不过从研究结果来看,阻断后血压增幅超过阻断前血压的60%可能会增加术后过度灌注综合征的风险。4.对比术中低灌注组和无低灌注组之间的术前临床资料显示高脂血症和年龄在两组之间有明显的区别(p<0.05),不过Logistic回归分析的结果表明只有年龄≥60岁是发生术中低灌注的危险因素(p<0.05)。结论返搏压与阻断后大脑中动脉血流速度之间无明显线性关系。返搏压指数并不比返搏压具有优势,返搏压在全麻情况下仍是一个较为可靠的监测指标,不会收到术中血压波动的影响,返搏压可能实时反映了当前血压状态下的脑血流灌注情况。我们建议对那些阻断后血压超过阻断前血压160%的患者在术后进行密切的临床观察和采取必要的干预措施,警惕过度灌注综合征的发生。我们推荐在全麻情况下以术中TCD监测为判断术中低灌注的标准,对于那些无法行TCD术中监测的患者可将返搏压作为判断术中低灌注的参考。而在术中TCD监测时需要警惕阻断后大脑中动脉血流速度消失和血流速度大于阻断前的患者,这两类患者的术后风险可能较大。更多还原

【Abstract】 ObjectCarotid endarterectomy has been proved a standard intervention for moderate-to-severe symptomatic and selected severe asymptomatic carotid stenosis. But its beneficial effects are limited by the perioperative complications. Cerebral monitoring and prediction of related complication play an important role in reducing the perioperative risk. This study was designed to research whether blood pressure would influence the accuracy of Stump pressure (SP) as a monitoring indicator of intraoperative hypoperfusion. We also attempted to find the risk factors of intraoperative hypoperfusion.MethodWe held a prospective clinical trial by recuiting176patients who underwent CEA under general anesthesia from2009to2012. Continuous TCD monitoring was performed during operation with measurement of MCAV. Systemic blood pressure (BP) was recorded at the same time. Stump pressure was recorded after clumping the carotid arteries. Shunting was used selectively. CT or MRI was performed if the neural symptoms happened. We analyzed the relationship between SP and MCAV. SP was compared with stump pressure index (SSI) to verify whether the SP should be corrected by systemic blood pressure. Multivariate logistic regression was used to find the risk factors of intraoperative hypoperfusion.Results1. There was no linear relationship between SP and MCAV during clamping (r=0.448, p<0.001). If the MCAV values were expressed as relative change of pre-clamping values, the correlation coefficient was still small (r=0.424, p<0.001).2. There were15patients whose MCAVs were reduced to0after clamping. The analysis demonstrated that these patients had more risk of postoperative TIA. There were14patients whose MCAVs after clamping were greater than the velocities before clamping. These patients did not show more risks of postoperative complications. However other researches pointed out that this kind of patients might have more postoperative risks.2. The AUCs of SP and SSI are both more than0.7. They are both accurate indicators in estimating intraoperative hypoperfusion. But there was no obvious difference between SP and SSI. It demonstrated that the fluctuation of intraoperative blood pressure had little effect on the accuracy of SP in estimating intraoperative hypoperfusion. So the blood pressure elevation after clumping the carotid would not influence the application of SP. However our research demonstrated that the patients would have more risk of cerebral hyperperfusion syndrome if the blood pressure after clamping was more than160%of the pre-clamping blood pressure.3. Compared with preoperative clinical factors, hyperlipidaemia and age showed the differences between the hypoperfusion group and the normal group (p<0.05). However the logistic regression results demonstrated that only age≥60was the risk factor of intraoperative hyperperfusion (p<0.05). The p value of hyperlipidaemia was more than0.05.ConclusionSSI was not superior to SP in estimating intraoperative hypoperfusion. SP was an accurate indicator under general anesthesia. If we took SP as a criterion of hyperperfusion, it was not necessary to correct SP by systemic blood pressure. We suggested that the blood pressure after clamping should not be higher than160%of the pre-clamping blood pressure. We also suggested TCD monitoring in evaluating intraoperative hypoperfusion under general anesthesia. It was meaningful to take SP as a criterion when some patients could not receive TCD monitoring. We should pay great attention to the patients whose clamping MCAV was0or greater than the pre-clamping MCAV during TCD monitoring.更多还原