Soukup J, Rieger A, Holz C, Miko I, Nemeth N, Menzel M
Department of Anesthesiology and Intensive Care Medicine, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
Acta Anaesthesiol Scand. 2007 Aug;51(7):872-9. doi: 10.1111/j.1399-6576.2007.01356.x.
The purpose of the present experimental study was to determine the feasibility and usefulness of brain temperature measurement (T(br)) and the calculated difference between brain temperature and arterial blood temperature (DeltaT(br-a)) in uninjured brain during variations of cerebral perfusion pressure (CPP) and concomitant changes of the regional cerebral blood flow (rCBF).
Nine anaesthetized pigs were subjected to controlled CPP decrease to assess the lower cerebral autoregulation threshold. A parenchymal intracranial pressure (ICP) sensor combined with a microthermistor for temperature measurement, a miniaturized Clark-type electrode measuring brain tissue oxygenation (p(ti)O(2)), a small flexible intraparenchymal thermodilution probe for measuring rCBF and cerebral microdialysis were inserted carefully in the frontal white matter.
Analysing the p(ti)O(2) during controlled CPP decrease, we found significant breakpoints of p(ti)O(2) at a CPP of 40 mmHg and 20 mmHg, related to an rCBF of 20 ml/100 g/min and approximately 10 ml/100 g/min. Similarly, the relationship between DeltaT(br-a), and CPP or rCBF revealed a characteristic increase of DeltaT(br-a) in the negative direction up to more than -0.30 degrees C assuming a strong flow dependency.
The temperature difference between brain tissue and arterial blood DeltaT(br-a) mainly reflects the cerebral blood flow-brain tissue oxygenation-metabolism relationship as far as the estimation of the individual lower cerebral autoregulation threshold.
本实验研究的目的是确定在脑灌注压（CPP）变化及局部脑血流（rCBF）伴随改变过程中，测量未受伤脑组织的脑温（T(br)）以及计算脑温与动脉血温度之间的差值（DeltaT(br-a)）的可行性和实用性。
对9只麻醉猪进行控制性降低CPP，以评估较低的脑自动调节阈值。将一个结合微热敏电阻用于温度测量的实质内颅内压（ICP）传感器、一个测量脑组织氧合（p(ti)O(2)）的小型化Clark型电极、一个用于测量rCBF的小型柔性实质内热稀释探头以及脑微透析探头小心地插入额叶白质。
在控制性降低CPP期间分析p(ti)O(2)时，我们发现在CPP为40 mmHg和20 mmHg时p(ti)O(2)有显著断点，分别对应rCBF为20 ml/100 g/min和约10 ml/100 g/min。同样，DeltaT(br-a)与CPP或rCBF之间的关系显示，在假设存在强烈流量依赖性的情况下，DeltaT(br-a)在负方向上有特征性增加，直至超过-0.30℃。
就个体较低脑自动调节阈值的估计而言，脑组织与动脉血之间的温差DeltaT(br-a)主要反映脑血流-脑组织氧合-代谢关系。
