主动脉弓手术停循环与脑灌注期间脑区域氧饱和度监测

Monitoring of regional cerebral oxygenation during deep hypothermic circulatory arrest with cerebral perfusion for aortic arch surgery

目的:明确深低温停循环(DHCA)与脑灌注相结合进行主动脉弓手术期间脑区域氧饱和度监测(rSO2)的价值。方法:28位病人的rSO2被监控,数据被统计分析。结果:DHCA的平均停循环时间是(59±17.1)min,外科手术的结果比较满意,住院期间死亡2例,死亡率(5.6%)。虽然全部病人兼有脑灌注支持,rSO2在DHCA期间仍然逐渐下降,平均降到(47±9.7)%,在复温末期又恢复到它的最初水平。有2位病人rSO2降低最明显,在长达83和88min的DHCA之后rSO2分别从57%和56%下降到27%和29%,这2位病人最终发展永久的神经系统损害。我们同时考察了End-rSO2和△-rSO2两个参数,在DHCA期间,脑灌注的灌注流速和这两个参数都存在线性相关。结论:(1)尽管DHCA和一定方式脑灌注的结合能提供大脑更有效的保护,这种保护措施仍然有一个安全的时限;(2)NIRS能实时监控脑rSO2,可用于监测大脑保护是否充分,有利于DHCA下脑灌注参数的调整。

Objective： To assess the value of monitoring of regional cerebral oxygen saturation （rSO2） during aortic arch surgery using deep hypothermic circulatory arrest （DHCA） in conjunction with three types of cerebral perfusion. Methods： The rSO2 of 28 patients was monitored non-invasively using near-infrared spectroscopy （NIRS） and the data were analyzed statistically. Results： The mean duration of DHCA with cerebral perfusion was （59± 17.1）min. Surgical outcomes were favorable with only two hospital deathes （5.6%）. However, the rSO2 decreased gradually in all patients during DHCA, even combined with any type of cerebral perfusion, and fell to （47±9.7）% on average. It did not change so greatly before DHCA and returned almostly to its initial level at the end of re-warming. Only two patients developed a permanent neurologic deficit, and this two patients showed the greatest decrease ofrSO2 from 57% to 27% and 56% to 29%, respectively after DHCA. Two parameters, End-rSO2 （the ratio of post- to pre-DHCA rSO2） and △-rSO2 （the rate of decrease from pre to post-DHCA rSO2） were obtained and there were linear correlations between the cerebral perfusion flow rate and each of these two parameters. Conelusions：（1）The study suggests that the combination of DHCA and three types of cerebral perfusion has a limit of safe duration in spite of its potential usefulness for brain protection, （2）and that rSO2 monitored by NIRS is useful in testing for adequate brain protection. It is hoped that monitoring of rSO2 can facilitate prediction of the safe duration of DHCA with cerebral perfusion and a more favorable adjustment of cerebral perfusion parameters.