Kakihana Yasuyuki, Matsunaga Akira, Yasuda Tomotsugu, Imabayashi Toru, Kanmura Yuichi, Tamura Mamoru
Kagoshima University Hospital, Division of Intensive Care Medicine, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
J Biomed Opt. 2008 May-Jun;13(3):033001. doi: 10.1117/1.2940583.
Near-infrared spectroscopy (NIRS) is a cerebral monitoring method that noninvasively and continuously measures cerebral hemoglobin oxygenation and the redox state of cytochrome oxidase using highly tissue-permeable near-infrared light. This technique now has wide clinical application, and its usefulness in the measurement of cerebral hemoglobin oxygenation has been confirmed under global cerebral injury and/or hypoxemic hypoxia; however, regional cerebral infarction located far from the monitoring site may not be detected by NIRS. Furthermore, the specificity and accuracy of the measurement of the redox state of cytochrome oxidase remain controversial. We apply NIRS to both animal and clinical investigations. Based on these results, we discuss the significance of the measurement of cerebral hemoglobin oxygenation and cytochrome oxidase in vivo and in clinical medicine. Using our algorithm, cytochrome oxidase signals are unaffected by hemoglobin signals, even when hematocrit values change from 35 to 5% under cardiopulmonary bypass in a dog model. In the clinical study, cytochrome oxidase during surgery is likely to be a good (though not perfect) predictor of postoperative cerebral outcome. NIRS appears to be a promising technology, but additional investigations are required to establish its clinical efficacy and justify its routine use during operative and perioperative periods.
近红外光谱技术（NIRS）是一种脑部监测方法，它使用具有高度组织穿透性的近红外光，非侵入性且连续地测量脑血红蛋白氧合情况以及细胞色素氧化酶的氧化还原状态。该技术目前在临床上有广泛应用，并且其在全脑损伤和/或低氧性缺氧情况下测量脑血红蛋白氧合的有效性已得到证实；然而，远离监测部位的局部脑梗死可能无法被NIRS检测到。此外，细胞色素氧化酶氧化还原状态测量的特异性和准确性仍存在争议。我们将NIRS应用于动物和临床研究。基于这些结果，我们讨论了在体内和临床医学中测量脑血红蛋白氧合和细胞色素氧化酶的意义。使用我们的算法，即使在犬模型体外循环期间血细胞比容值从35%变为5%时，细胞色素氧化酶信号也不受血红蛋白信号的影响。在临床研究中，手术期间的细胞色素氧化酶可能是术后脑部预后的一个良好（尽管并不完美）预测指标。NIRS似乎是一项很有前景的技术，但需要进一步研究以确定其临床疗效，并证明其在手术及围手术期常规使用的合理性。
