Staub F, Graf R, Gabel P, Köchling M, Klug N, Heiss W D
Department of Neurosurgery, University of Cologne, Germany.
Neurosurgery. 2000 Nov;47(5):1106-15; discussion 1115-6. doi: 10.1097/00006123-200011000-00016.
Intracerebral microdialysis is a tool to monitor metabolic disturbances in the brains of patients with severe head injuries or subarachnoid hemorrhage (SAH). In the search for putative indicators of primary and secondary brain damage, we measured multiple metabolites in the dialysates of patients with SAH, to elucidate their significance for the outcomes of the patients as well as their temporal profiles of liberation after the insult.
Microdialysis probes were placed, with a ventriculostomy catheter for drainage of cerebrospinal fluid, into a frontal lobe of 10 patients with aneurysmal SAH, for 4.6 +/- 0.5 days. Amino acids, metabolites of glycolysis, purines, catecholamines, and nitric oxide oxidation byproducts were measured by high-performance liquid chromatography. Spearman's correlation coefficient and Student's t test were used to compare the levels of the metabolites with the outcomes of the patients, as assessed using the Glasgow Outcome Scale, 3 months after the ictus.
For patients with unfavorable outcomes (Glasgow Outcome Scale scores of 1-3), which were primarily associated with the development of large infarctions, dialysate levels of excitatory amino acids increased up to 30-fold, those of lactate up to 10-fold, and those of nitrite up to 5-fold, compared with normal levels observed for patients with favorable outcomes (Glasgow Outcome Scale scores of 4 or 5). When average peak concentrations in the dialysates of patients with favorable and unfavorable outcomes were compared, significantly higher levels of excitatory amino acids, taurine, lactate, and nitrite, but not of purines and catecholamines, were observed for those with poor outcomes (P < 0.05). With respect to the temporal profiles of the average metabolite concentrations, the significantly increased levels of amino acids observed for patients with poor outcomes followed a biphasic course, with maximal concentrations on the first and second days or the seventh day after the insult (P < 0.01).
These data confirm the usefulness of excitatory amino acids and lactate as major parameters for neurochemical monitoring for patients threatened by acute cerebral disorders. Other substances, such as taurine and nitrite, were also demonstrated to be potentially predictive. Release of these substances into the extracellular fluid of the brain might be particularly relevant for the development of secondary brain damage after SAH, e.g., infarction or brain swelling.
脑微透析是监测重型颅脑损伤或蛛网膜下腔出血（SAH）患者脑内代谢紊乱的一种工具。为寻找原发性和继发性脑损伤的潜在指标，我们检测了SAH患者透析液中的多种代谢物，以阐明它们对患者预后的意义及其在损伤后释放的时间变化情况。
将微透析探针与用于引流脑脊液的脑室造瘘导管一起置于10例动脉瘤性SAH患者的额叶，放置4.6±0.5天。采用高效液相色谱法检测氨基酸、糖酵解代谢物、嘌呤、儿茶酚胺和一氧化氮氧化产物。使用Spearman相关系数和Student t检验比较代谢物水平与患者预后，预后评估采用发病3个月后的格拉斯哥预后量表。
预后不良（格拉斯哥预后量表评分为1 - 3分）的患者主要与大面积梗死的发生有关，与预后良好（格拉斯哥预后量表评分为4或5分）患者的正常水平相比，其透析液中兴奋性氨基酸水平升高达30倍，乳酸水平升高达10倍，亚硝酸盐水平升高达5倍。比较预后良好和不良患者透析液中的平均峰值浓度，发现预后不良者的兴奋性氨基酸、牛磺酸、乳酸和亚硝酸盐水平显著更高，但嘌呤和儿茶酚胺水平无显著差异（P < 0.05）。关于平均代谢物浓度的时间变化情况，预后不良患者中观察到的氨基酸水平显著升高呈双相过程，在损伤后的第一天和第二天或第七天达到最高浓度（P < 0.01）。
这些数据证实了兴奋性氨基酸和乳酸作为急性脑疾病威胁患者神经化学监测主要参数的有用性。其他物质，如牛磺酸和亚硝酸盐，也被证明具有潜在的预测价值。这些物质释放到脑外液中可能与SAH后继发性脑损伤（如梗死或脑肿胀）的发生特别相关。
