不同吸入麻醉剂对人脑葡萄糖代谢率的影响

Effects of different volatile anesthetics on cerebral glucose metabolism rate in human

目的:应用正电子发射断层扫描技术(PET),研究吸入异氟醚和安氟醚麻醉对健康志愿者脑内葡萄糖代谢率(CMRglu)的影响。方法:选择8名志愿者,每位志愿者分别做3次PET扫描,采用PHILIPSCPETPlus扫描仪及18FDG标记技术测定CMRglu,第1次在清醒状态下扫描作为对照,第2、3次分别吸入异氟醚和安氟醚麻醉直至意识丧失。结果:清醒时全脑CMRglu平均为(30.0±1.1)μmol/(100mg·min),与清醒时比较,异氟醚麻醉降低全脑CMRglu22%至(23.3±1.4)μmol/(100mg·min)(P<0.05),安氟醚麻醉降低全脑CMRglu19%至(24.4±0.9)μmol/(100mg·min)(P<0.05);吸入异氟醚或安氟醚麻醉后脑内局部葡萄糖代谢率(rCMRglu)均显著降低,其中异氟醚麻醉下以丘脑、舌回和扣带回葡萄糖代谢率降低更为显著(P<0.01);而安氟醚麻醉下丘脑、舌回、扣带回、额叶和桥脑等脑区葡萄糖代谢率的降低最显著(P<0.01)。结论:全脑及脑内局部葡萄糖代谢率在吸入异氟醚和安氟醚麻醉时均可显著降低,异氟醚和安氟醚麻醉在人脑内的靶区有一定的相似性,但不完全相同。

Objective To investigate the effects of different volatile anesthetics on cerebral glucose metabolism rate （CMRglu） of healthy volunteers using positron emission topography（PET） . Methods Eight volunteers each underwent three PET scan： one scan assessed awake-baseline metabolism and other two scans assessed metabolism during isoflumne and enflurane anesthesia. Scans were obtained with a PHILIPS CPET Plus scanner （2.0 mm resolution-FWHM ） using the ^18fluorodeoxyglucose technique. Results Awake whole-brain glucose metabolism averaged （30.0 ± 1.1 ）μmol/ （100 mg·min ）, isoflurane anesthesia decreased by 22% of the whole-brain CMRglu to （23.3 ± 1.4 ） μmol/（ 100 mg·min） （P 〈 0. 05 ）, but enflurane decreased by 19% of the whole-brain CMRglu to （24.4 ± 0.9 ）μmol/（ 100 mg·min） （P 〈 0.05）; Regional cerebral glucose metabolism rate（rCMRglu） also decreased throughout the brain, especially thalamus, lingual gyrus, and cingulated gyrus during isoflurane anesthesia （P 〈 0. 01 ）, and thalamns, lingual gyrus, frontal lobe, pons and cingtlated gyrus during enflurane anesthesia （P 〈 0.01 ） . Conclusion Whole-brain and regional metabolism decrease significantly during both isoflurane and enflurane anesthesia, but the targets of the two anesthetics are partly different.