Intracerebral microdialysis in neurointensive care:: the use of urea as an endogenous reference compound
Intracerebral microdialysis in neurointensive care:: the use of urea as an endogenous reference compound
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DOI：
10.3171/jns.2001.94.3.0397
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发表时间：
2001-03-01
影响因子：
4.1
通讯作者：
Hillered, L
中科院分区：
文献类型：
--
作者：
Ronne-Engström, E;Cesarini, KG;Hillered, L
物体。在评价脑内微透析的结果时，必须考虑微透析探头的体内性能，因为这决定了微透析样本中获得的间质浓度的比例。在体内的表现取决于几个因素，例如，间质的扩散特性，这些特性在急性脑损伤过程中可能会发生变化。本研究通过比较尿素在脑(CNS)、腹部皮下组织(SC)和血清(BS)中的水平，探讨了用均匀分布于各体液室的尿素作为内源性参比化合物控制体内行为的方法。69名创伤性脑损伤或脑血管疾病患者参加了这项研究。在这些患者中，63例使用了中枢神经系统探头，40例使用了SC探头，34例同时使用了两者。在床边对微透析样品进行尿素测定，对BS样品在常规临床实验室研究中对尿素进行测定，并对探头进行校准以得到相同的结果。CNS/SC尿素的相关系数为0.88(2414份)，CNS/BS尿素的相关系数为0.89(180份)，SC/BS尿素的相关系数为0.98(112份)。中枢神经系统、SC和BS的尿素水平高度相关，支持尿素均匀分布的假设。因此，CNS/SC尿素比率可用于监测CNS探针的体内性能。微透析测量的其他物质的波动可能是由大脑中的生物变化引起的，只要CNS/SC尿素比率保持不变。
Object. When evaluating the results of intracerebral microdialysis, the in vivo performance of the microdialysis probe must be considered, because this determines the fraction of the interstitial concentration obtained in the microdialysis samples. The in vivo performance is dependent on several factors, for example, the interstitial compartment's diffusion characteristics, which may vary during the course of the acute brain injury process. In the present study the authors investigated the method of controlling the in vivo performance by using urea, which is evenly distributed in all body fluid compartments, as an endogenous reference compound and by comparing the urea levels in three compartments: the brain (CNS), abdominal subcutaneous tissue (SC), and blood serum (BS).Methods. Sixty-nine patients with traumatic brain injury or cerebrovascular disease were included in the study. In 63 of these patients a CNS probe was used, an SC probe was used in 40, and both were used in 34. Urea was measured by enzymatic methods, at bedside for the microdialysis samples and in routine clinical laboratory studies for the BS samples, with the probe calibrated to give identical results. The correlation coefficient for CNS/SC urea was 0.88 (2414 samples), for CNS/BS urea it was 0.89 (180 samples), and for SC/BS urea it was 0.98 (112 samples).Conclusions. Urea levels in the CNS, SC, and BS were highly correlated, which supports the assumption that urea is evenly distributed. The CNS/SC urea ratio can therefore be used for monitoring the CNS probe's in vivo performance. Fluctuations in other substances measured with microdialysis are probably caused by biological changes in the brain, as long as the CNS/SC urea ratio remains constant.