Smielewski P, Czosnyka M, Pickard J D, Kirkpatrick P
MRC Cambridge Centre for Brain Repair, Addenbrooke's Hospital, University of Cambridge, U.K.
Acta Neurochir Suppl. 1998;71:263-5. doi: 10.1007/978-3-7091-6475-4_76.
The aim of this study was to assess Near-infrared spectroscopy (NIRS) as a tool for testing CO2 reactivity in patients with carotid occlusive disease. One hundred sixty patients were examined (age range 44 to 85 years). Monitored parameters included transcranial Doppler flow velocity (FV), changes in concentration of oxy-(HbO2) and deoxy (Hb) haemoglobin, cutaneous Laser Doppler blood flow (LDF), endtidal CO2, ABP, and SaO2. Hypercapnia was induced using a 5% CO2 air mixture for inhalation. To estimate the skin flow contribution to NIRS during reactivity testing, the superficial temporal artery was compressed, and the NIRS changes in response to the fall in LDF recorded. FV and HbO2 derived reactivity values were related to the severity of the stenosis (p = 0.0001 and 0.021 respectively). The correlation between the two modalities was significant (r = 0.47, p < 0.000001). The average estimated skin contribution to NIRS changes was 16.5%. Reproducibility of HbO2-reactivity was similar but worse than FV reactivity (19.1% and 13.8% variation respectively). The clinical correlations improved when our method of correction for skin influence was used. NIRS shows potential as an alternative technique for testing CO2 reactivity in patients with carotid disease provided the conditions are carefully controlled and the contribution from extracranial tissue is taken into account.
本研究旨在评估近红外光谱技术（NIRS）作为检测颈动脉闭塞性疾病患者二氧化碳反应性的一种工具。共检查了160例患者（年龄范围44至85岁）。监测参数包括经颅多普勒血流速度（FV）、氧合血红蛋白（HbO2）和脱氧血红蛋白（Hb）浓度变化、皮肤激光多普勒血流（LDF）、呼气末二氧化碳、动脉血压（ABP）和血氧饱和度（SaO2）。使用5%二氧化碳空气混合物吸入诱导高碳酸血症。为了评估反应性测试期间皮肤血流对NIRS的贡献，压迫颞浅动脉，并记录LDF下降时NIRS的变化。FV和HbO2衍生的反应性值与狭窄严重程度相关（分别为p = 0.0001和0.021）。两种方法之间的相关性显著（r = 0.47，p < 0.000001）。皮肤对NIRS变化的平均估计贡献为16.5%。HbO2反应性的可重复性相似，但比FV反应性差（分别为19.1%和13.8%的变化）。当使用我们校正皮肤影响的方法时，临床相关性得到改善。如果条件得到仔细控制并考虑颅外组织的贡献，NIRS显示出作为检测颈动脉疾病患者二氧化碳反应性的替代技术的潜力。
