From the Department of Anesthesiology, Section of Neuroanesthesia (K.U.K., N.J., L.N., M.R.) Department of Nuclear Medicine and PET Center (J.A.) Department of Neurosurgery (G.v.O.) Department of Neuroradiology (L.Ø.), Aarhus University Hospital, Aarhus, Denmark Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark (I.K.M., L.Ø.) Department of Anesthesiology, Horsens Regional Hospital, Horsens, Denmark (U.S.E.) Institute of Neuroradiology, Charité, Universitätsmedizin, Berlin, Germany (A.T.).
Anesthesiology. 2020 Aug;133(2):304-317. doi: 10.1097/ALN.0000000000003377.
Studies in anesthetized patients suggest that phenylephrine reduces regional cerebral oxygen saturation compared with ephedrine. The present study aimed to quantify the effects of phenylephrine and ephedrine on cerebral blood flow and cerebral metabolic rate of oxygen in brain tumor patients. The authors hypothesized that phenylephrine reduces cerebral metabolic rate of oxygen in selected brain regions compared with ephedrine.
In this double-blinded, randomized clinical trial, 24 anesthetized patients with brain tumors were randomly assigned to ephedrine or phenylephrine treatment. Positron emission tomography measurements of cerebral blood flow and cerebral metabolic rate of oxygen in peritumoral and normal contralateral regions were performed before and during vasopressor infusion. The primary endpoint was between-group difference in cerebral metabolic rate of oxygen. Secondary endpoints included changes in cerebral blood flow, oxygen extraction fraction, and regional cerebral oxygen saturation.
Peritumoral mean ± SD cerebral metabolic rate of oxygen values before and after vasopressor (ephedrine, 67.0 ± 11.3 and 67.8 ± 25.7 μmol · 100 g · min; phenylephrine, 68.2 ± 15.2 and 67.6 ± 18.0 μmol · 100 g · min) showed no intergroup difference (difference [95% CI], 1.5 [-13.3 to 16.3] μmol · 100 g · min [P = 0.839]). Corresponding contralateral hemisphere cerebral metabolic rate of oxygen values (ephedrine, 90.8 ± 15.9 and 94.6 ± 16.9 μmol · 100 g · min; phenylephrine, 100.8 ± 20.7 and 96.4 ± 17.7 μmol · 100 g · min) showed no intergroup difference (difference [95% CI], 8.2 [-2.0 to 18.5] μmol · 100 g · min [P = 0.118]). Ephedrine significantly increased cerebral blood flow (difference [95% CI], 3.9 [0.7 to 7.0] ml · 100 g · min [P = 0.019]) and regional cerebral oxygen saturation (difference [95% CI], 4 [1 to 8]% [P = 0.024]) in the contralateral hemisphere compared to phenylephrine. The change in oxygen extraction fraction in both regions (peritumoral difference [95% CI], -0.6 [-14.7 to 13.6]% [P = 0.934]; contralateral hemisphere difference [95% CI], -0.1 [- 12.1 to 12.0]% [P = 0.989]) were comparable between groups.
The cerebral metabolic rate of oxygen changes in peritumoral and normal contralateral regions were similar between ephedrine- and phenylephrine-treated patients. In the normal contralateral region, ephedrine was associated with an increase in cerebral blood flow and regional cerebral oxygen saturation compared with phenylephrine.
在麻醉患者中的研究表明，与麻黄碱相比，去氧肾上腺素可降低局部脑氧饱和度。本研究旨在定量研究去氧肾上腺素和麻黄碱对脑肿瘤患者脑血流和脑氧代谢率的影响。作者假设去氧肾上腺素与麻黄碱相比，可降低选定脑区的脑氧代谢率。
在这项双盲、随机临床试验中，24 例脑肿瘤麻醉患者被随机分为麻黄碱或去氧肾上腺素治疗组。在血管加压素输注前后，进行正电子发射断层扫描测量肿瘤周围和正常对侧区域的脑血流和脑氧代谢率。主要终点是组间脑氧代谢率的差异。次要终点包括脑血流、氧摄取分数和局部脑氧饱和度的变化。
血管加压素（麻黄碱，67.0 ± 11.3 和 67.8 ± 25.7 μmol·100 g·min；去氧肾上腺素，68.2 ± 15.2 和 67.6 ± 18.0 μmol·100 g·min）前后肿瘤周围区域的平均脑氧代谢率（±SD）值无组间差异（差异[95%CI]，1.5[-13.3 至 16.3]μmol·100 g·min[P = 0.839]）。相应的对侧大脑半球脑氧代谢率值（麻黄碱，90.8 ± 15.9 和 94.6 ± 16.9 μmol·100 g·min；去氧肾上腺素，100.8 ± 20.7 和 96.4 ± 17.7 μmol·100 g·min）无组间差异（差异[95%CI]，8.2[-2.0 至 18.5]μmol·100 g·min[P = 0.118]）。与去氧肾上腺素相比，麻黄碱显著增加了对侧半球的脑血流（差异[95%CI]，3.9[0.7 至 7.0]ml·100 g·min[P = 0.019]）和局部脑氧饱和度（差异[95%CI]，4[1 至 8]%[P = 0.024]）。两个区域的氧摄取分数变化（肿瘤周围区域差异[95%CI]，-0.6[-14.7 至 13.6]%[P = 0.934]；对侧半球差异[95%CI]，-0.1[-12.1 至 12.0]%[P = 0.989]）在两组之间相似。
与去氧肾上腺素和麻黄碱治疗的患者相比，肿瘤周围和正常对侧区域的脑氧代谢率变化相似。在正常对侧区域，与去氧肾上腺素相比，麻黄碱可增加脑血流和局部脑氧饱和度。
