应用PET技术探讨咪唑安定对人脑葡萄糖代谢的影响

Imaging study of cerebral glucose metabolism during midazolam anesthesia in humans with positron emission tomography

目的:应用正电子发射计算机断层扫描显像(PET) 技术研究咪唑安定麻醉对健康志愿者脑内葡萄糖代谢 (CMGlu)的影响,探明咪唑安定麻醉在脑内的可能作用部位. 方法:选择志愿者8名,每位志愿者分别做2次PET扫描,采 用PHILIPSCPETPlus扫描仪及18F FDG标记技术测定 CMGlu,第1次在清醒状态下扫描作为对照,第2次在咪唑安 定靶控输注(TCI效应室浓度为80μg/L)麻醉下,将两次结果 进行比较.结果:清醒时全脑内CMGlu计数为1870±193,咪 唑安定麻醉后CMGlu计数即降低至1632±174(P<0.05),降 低12%.与清醒组比较,咪唑安定麻醉后脑内多数区域 CMGlu计数显著降低(P<0.05),而以丘脑、扣带回和左侧额 叶CMGlu计数降低更为显著(P<0.01),分别降低33%, 28%和25%.结论:全脑及脑内多数区域CMGlu在咪唑安定 麻醉后可显著降低,丘脑。

AIM: To examine the changes in regional cerebral glucose metabolism induced by midazolam anesthesia in volunteers using positron emission tomography (PET) technology and to investigate its possible action site in brain. METHODS: Eight volunteers underwent two PET scanning: one assessed awake-baseline metabolism and the other assessed metabolism during midazolam anesthesia. A PHILIPS CPET Plus scanner (2.0 mm resolution-FWHM) and the 18 fluorodeoxyglucose technique were applied. RESULTS: The awake whole-brain glucose metabolic count averaged 1870±193, and midazolam anesthesia reduced the whole-brain glucose metabolic count by 12% to 1632±174(P<0.05). The regional cerebral glucose metabolic count also decreased in most cerebral regions, especially thalamus, left prefrontal cortex and cingulated gyrus (P<0.01), decreasing by 33%, 28% and 25% respectively. CONCLUSION: Whole-brain and most regional metabolism decrease significantly during midazolam anesthesia. Thalamus, left prefrontal cortex and cingulated gyrus are most sensitive to midazolam and they may be the primary targets in midazolam anesthesia.