皮质热清除作为即将到来的神经退化的预测因子。

M S Choksey
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引用次数: 0

摘要

脑血流(CBF)对脑组织的灌注至关重要。在急性神经外科疾病,特别是蛛网膜下腔出血和头部损伤中,它经常被打乱。尽管它很重要,但在临床实践中,常规测量CBF并不常见,因为CBF的变化可能会突然发生。然而,一种监测脑血流的方法可能是有用的,特别是如果在神经系统恶化之前可以获得即将发生的缺血的警告。自1933年以来,组织热清除率的测量已被用作局部组织血流量的估计。它的历史充满了争议,主要集中在量化方面。作为第一个近似,灌注组织的清热能力是两个成分的总和:一个与组织成分有关的固定成分,主要是水含量,另一个与局部血流有关的可变对流成分。流动与观测到的热间隙增量之间的数学关系仍有争议。在这里,回顾了热间隙的历史,并描述了我们用一个相对简单的装置工作的结果。它由一个植入式探针组成,设计用于测量任意清除单位(CU)的皮质表面热清除,范围从27 CU(尸体)到69 CU(灌注良好的大脑)。术前和术后研究表明,该系统能够快速跟踪血流的变化。对24例动脉瘤术后患者进行术后皮质热清除率(CTC)监测。大多数保持临床稳定,热清除率超过50 CU。然而,在其他研究中,发现低热清除率或下降热清除率与神经功能障碍的发展有关。通过对受者工作特征曲线的分析,该方法检测对侧缺血性运动缺陷的灵敏度为0.86,特异性为0.82。CTC高于50 CU的患者没有出现新的神经功能缺损,而CTC低于35的患者则出现了新的神经功能缺损。证据-历史,数学,实践和理论- CTC是密切相关的局部血流进行了讨论。热清除率的变化在缺血性神经退化发展之前已被观察到。随着改善皮质血流的手段变得越来越广泛,检测即将发生的缺血可能变得越来越重要。这种早期发现和随后的治疗是否会导致更好的患者预后仍有待确定。我相信会的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Cortical thermal clearance as a predictor of imminent neurological deterioration.

Cerebral blood flow (CBF) is vital for the perfusion of brain tissue. It is frequently deranged in acute neurosurgical disorders, particularly subarachnoid haemorrhage and head injury. Despite its importance, in clinical practice the routine measurement of CBF is uncommon, as changes in CBF can occur abruptly. However, a method of CBF monitoring may be potentially useful, particularly if warning could be obtained of impending ischaemia before neurological deterioration. Measurement of tissue thermal clearance has been used as an estimate of local tissue blood flow since 1933. Its history is full of controversy, mostly centred around quantification. The ability of perfused tissues to clear heat is, as a first approximation, the sum of two components: a fixed component related to the constituents of the tissue, primarily the water content, and a variable convective component, related to the local blood flow. The mathematical relationship between flow and the observed increment in thermal clearance is still debatable. Here, the history of thermal clearance is reviewed, and the results of our work with a relatively simple device are described. It consisted of an implantable probe, designed to measure the thermal clearance of the cortical surface in arbitrary clearance units (CU), ranging from 27 CU (cadaveric) to 69 CU (well perfused brain). Pre- and postoperative studies showed that the system was capable of following changes in blood flow rapidly. The cortical thermal clearance (CTC) was monitored postoperatively in 24 patients after aneurysm surgery. Most remained clinically stable and had thermal clearances over 50 CU. In others, however, it was seen that a low-or falling-thermal clearance was associated with development of a neurological deficit. Analysis using receiver operating characteristics curves established that the method had a sensitivity of 0.86 and a specificity of 0.82 in the detection of a contralateral ischaemic motor deficit. No patient in whom the CTC remained above 50 CU ever developed a new neurological deficit, whereas all patients with a CTC below 35 did. The evidence-historical, mathematical, practical, and theoretical-that CTC is closely related to local blood flow is discussed. Changes in thermal clearance have been observed prior to the development of ischaemic neurological deterioration. Detection of imminent ischaemia may become increasingly important as means of improving cortical blood flow become more widely available. Whether such early detection- and subsequent treatment-of ischaemia will result in better patient outcome remains to be established. I believe it will.

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