University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
Neurocrit Care. 2011 Dec;15(3):609-22. doi: 10.1007/s12028-011-9517-8.
Microdialysis, an in vivo technique that permits collection and analysis of small molecular weight substances from the interstitial space, was developed more than 30 years ago and introduced into the clinical neurosciences in the 1990s. Today cerebral microdialysis is an established, commercially available clinical tool that is focused primarily on markers of cerebral energy metabolism (glucose, lactate, and pyruvate) and cell damage (glycerol), and neurotransmitters (glutamate). Although the brain comprises only 2% of body weight, it consumes 20% of total body energy. Consequently, the ability to monitor cerebral metabolism can provide significant insights during clinical care. Measurements of lactate, pyruvate, and glucose give information about the comparative contributions of aerobic and anaerobic metabolisms to brain energy. The lactate/pyruvate ratio reflects cytoplasmic redox state and thus provides information about tissue oxygenation. An elevated lactate pyruvate ratio (>40) frequently is interpreted as a sign of cerebral hypoxia or ischemia. However, several other factors may contribute to an elevated LPR. This article reviews potential non-hypoxic/ischemic causes of an increased LPR.
微透析技术是一种活体技术，可从细胞间隙中收集和分析小分子物质，该技术于 30 多年前开发，并于 20 世纪 90 年代引入临床神经科学领域。如今，脑微透析技术已成为一种成熟的商业化临床工具，主要关注于脑能量代谢（葡萄糖、乳酸和丙酮酸）和细胞损伤（甘油）以及神经递质（谷氨酸）的标志物。尽管大脑仅占体重的 2%，但其消耗的能量占全身总能量的 20%。因此，监测脑代谢的能力在临床护理中可以提供重要的见解。乳酸、丙酮酸和葡萄糖的测量可提供有关有氧和无氧代谢对脑能量相对贡献的信息。乳酸/丙酮酸比值反映细胞质的氧化还原状态，从而提供有关组织氧合的信息。升高的乳酸/丙酮酸比值（>40）通常被解释为脑缺氧或缺血的迹象。然而，其他几个因素也可能导致 LPR 升高。本文回顾了升高的 LPR 的潜在非缺氧/缺血原因。
