【罂粟摘要】深低温停循环期间持续脑氧摄取与术后脑损伤的关系
深低温停循环期间持续脑氧摄取与术后脑损伤的关系
贵州医科大学 麻醉与心脏电生理课题组
翻译：吴学艳 编辑：佟睿 审校：曹莹
心脏手术中体外循环通常在深低温(～18°C)下进行，以降低组织氧需、提供脑保护；关于体外循环并深低温停循环(DHCA)对先天性心脏病患儿神经系统发育预后的影响目前研究尚有争议。在这里，我们通过量化新生儿DHCA期间脑氧饱和度、脑血流量及脑氧代谢的变化，探讨以上变化与术后脑损伤的关系。
采用弥漫性光谱学(DOS)和弥漫性相关光谱学(DCS)两种无创光学技术，对接受DHCA治疗的危重先天性心脏病患儿进行术中持续监测脑氧饱和度(ScO2)和脑血流指数(CBFi)；行术前、术后脑磁共振成像(MRI)检测脑白质损伤(WMI)情况。
纳入15例新生儿进行研究，其中11/15例已接受脑MRI检查；在DHCA过程中，ScO2随时间呈指数衰减，中位衰减率为-0.04min-1。这一衰退率在不同受试者之间差异较大；在DHCA期间ScO2下降幅度较大的受试者更有可能发生术后WMI(p=0.02)。
结论
DHCA期间脑氧摄取持续存在，不同患儿脑氧摄取差异较大；患儿DHCA期间脑氧摄取程度越高，术后MRI中显示新的WMI可能性更大。以上研究表明；在DHCA期间应监测脑氧摄取，以明确患儿存在缺氧缺血性脑损伤的风险，而目前使用的商业脑氧监测仪可能低估了脑氧摄取。
Lynch JM, Mavroudis CD, Ko TS,et al. Association of ongoing cerebral oxygen extraction during deep hypothermic circulatory arrest with post-operative brain injury. Semin Thorac Cardiovasc Surg[J]. 2021 Sep 8:S1043-0679(21)00405-6.DOI: 10.1053/j.semtcvs.2021.08.026.
Association of ongoing cerebral oxygen extraction during deep hypothermic circulatory arrest with post-operative brain injury
Abstract
Objective: Cardiac surgery utilizing circulatory arrest is most commonly performed under deep hypothermia (~18°C) to suppress tissue oxygen demand and provide neuroprotection during operative circulatory arrest. Studies investigating the effects of deep hypothermic circulatory arrest (DHCA) on neurodevelopmental outcomes of patients with congenital heart disease give conflicting results. Here, we address these issues by quantifying changes in cerebral oxygen saturation, blood flow, and oxygen metabolism in neonates during DHCA and investigating the association of these changes with postoperative brain injury.
Methods: Neonates with critical congenital heart disease undergoing DHCA were recruited for continuous intraoperative monitoring of cerebral oxygen saturation (ScO2) and an index of cerebral blood flow (CBFi) using two non-invasive optical techniques, diffuse optical spectroscopy (DOS) and diffuse correlation spectroscopy (DCS). Pre- and post-operative brain magnetic resonance imaging (MRI) was performed to detect white matter injury (WMI).
Results: Fifteen neonates were studied, and 11/15 underwent brain MRI. During DHCA, ScO2 decreased exponentially in time with a median decay rate of -0.04 min-1. This decay rate was highly variable between subjects. Subjects who had larger decreases in ScO2 during DHCA were more likely to have post-operative WMI (p=0.02).
Conclusions: Cerebral oxygen extraction persists during DHCA and varies widely from patient-to-patient. Patients with a higher degree of oxygen extraction during DHCA were more likely to show new WMI in post-operative MRI. These findings suggest cerebral oxygen extraction should be monitored during DHCA to identify patients at risk for hypoxic-ischemic injury, and that current commercial cerebral oximeters may underestimate cerebral oxygen extraction.