Abstract：
After traumatic brain injury (TBI), cerebral metabolism can become deranged, contributing to secondary injury. Cerebral microdialysis (CMD) allows cerebral metabolism assessment and is often used with other neuro-monitoring modalities. CMD-derived parameters such as the lactate/pyruvate ratio (LPR) show a failure of oxidative energy generation. CMD-based abnormal metabolic states can be described following TBI, informing the etiology of physiological derangements. This systematic review summarizes the published literature on microdialysis-based abnormal metabolic classifications following TBI. Original research studies in which the populations were patients with TBI were included. Studies that described CMD-based classifications of metabolic abnormalities were included in the synthesis of the narrative results. A total of 825 studies underwent two-step screening after duplicates were removed. Fifty-three articles that used CMD in TBI patients were included. Of these, 14 described abnormal metabolic states based on CMD parameters. Classifications were heterogeneous between studies. LPR was the most frequently used parameter in the classifications; high LPR values were described as metabolic crisis. Ischemia was consistently defined as high LPR with low CMD substrate levels (glucose or pyruvate). Mitochondrial dysfunction, describing inability to use energy substrate despite availability, was identified based on raised LPR with near-normal levels of pyruvate. This is the first systematic review summarizing the published literature on microdialysis-based abnormal metabolic states following TBI. Although variability exists among individual classifications, there is broad agreement about broad definitions of metabolic crisis, ischemia, and mitochondrial dysfunction. Identifying the etiology of deranged cerebral metabolism after TBI is important for targeting therapeutic interventions.
摘要：
创伤性脑损伤（TBI）后，大脑代谢会变得紊乱，造成二次伤害。脑微透析（CMD）可以评估脑代谢，并且通常与其他神经监测方式一起使用。CMD衍生的参数如乳酸/丙酮酸盐比率(LPR)显示氧化能产生失败。基于CMD的异常代谢状态可以在TBI之后描述，告知生理紊乱的病因。本系统综述总结了关于TBI后基于微透析的异常代谢分类的已发表文献。包括人群为TBI患者的原始研究研究。描述基于CMD的代谢异常分类的研究包括在叙事结果的合成中。总共825项研究在去除重复项后进行两步筛选。包括53篇在TBI患者中使用CMD的文章。其中,图14描述了基于CMD参数的异常代谢状态。研究之间的分类是异质的。LPR是分类中最常用的参数；高LPR值被描述为代谢危机。缺血被一致地定义为高LPR和低CMD底物水平(葡萄糖或丙酮酸)。线粒体功能障碍,描述尽管可用，但无法使用能量底物，是根据丙酮酸水平接近正常水平的LPR升高确定的。这是总结TBI后基于微透析的异常代谢状态的已发表文献的第一个系统综述。尽管各个分类之间存在差异，关于代谢危机的广泛定义有广泛的共识，缺血,和线粒体功能障碍。确定TBI后脑代谢紊乱的病因对于靶向治疗干预很重要。
