Rapid magnetic resonance measurement of global cerebral metabolic rate of oxygen consumption in humans during rest and hypercapnia
Rapid magnetic resonance measurement of global cerebral metabolic rate of oxygen consumption in humans during rest and hypercapnia
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DOI：
10.1038/jcbfm.2011.34
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发表时间：
2011-07-01
影响因子：
6.3
通讯作者：
Wehrli, Felix W.
中科院分区：
文献类型：
--
作者：
Jain, Varsha;Langham, Michael C.;Wehrli, Felix W.
高碳酸血症对脑耗氧代谢率（CMRO 2）的影响一直是深入研究和争论的主题。大多数高碳酸血症的应用是基于这样的假设，即二氧化碳分压的轻度增加对脑代谢的影响可以忽略不计。在这项研究中，我们试图通过同时测量全球静脉血氧饱和度（SvO 2）和总脑血流量（tCBF），时间分辨率为30秒，使用磁共振血流测量和相位对比技术在10个健康清醒的成年人进一步调查高碳酸血症的血管和代谢的影响。高碳酸血症时SvO 2和tCBF显著升高（P < 0.005），CMRO 2无明显变化（P > 0.05）。此外，发现tCBF和潮气末二氧化碳（R-2 = 0.72，P < 0.005）以及基线SvO 2和tCBF（R-2 = 0.72，P < 0.005）的分数变化相关。数据还表明脑血管反应性（CVR）与基线tCBF之间存在相关性（R-2 = 0.44，P = 0.052）。使用线性拟合模型确定CVR值为6.1% +/- 1.6%/mmHg。此外，在6名受试者从高碳酸血症恢复后，观察到SvO 2和tCBF平均低于6.7% +/- 4%和17.1% +/- 7%。Journal of Cerebral Blood Flow & Metabolism（2011）31，1504-1512; doi：10.1038/jcbfm.2011.34; 2011年4月20日在线发表
The effect of hypercapnia on cerebral metabolic rate of oxygen consumption (CMRO2) has been a subject of intensive investigation and debate. Most applications of hypercapnia are based on the assumption that a mild increase in partial pressure of carbon dioxide has negligible effect on cerebral metabolism. In this study, we sought to further investigate the vascular and metabolic effects of hypercapnia by simultaneously measuring global venous oxygen saturation (SvO2) and total cerebral blood flow (tCBF), with a temporal resolution of 30 seconds using magnetic resonance susceptometry and phase-contrast techniques in 10 healthy awake adults. While significant increases in SvO2 and tCBF were observed during hypercapnia (P < 0.005), no change in CMRO2 was noted (P > 0.05). Additionally, fractional changes in tCBF and end-tidal carbon dioxide (R-2 = 0.72, P < 0.005), as well as baseline SvO2 and tCBF (R-2 = 0.72, P < 0.005), were found to be correlated. The data also suggested a correlation between cerebral vascular reactivity (CVR) and baseline tCBF (R-2 = 0.44, P = 0.052). A CVR value of 6.1% +/- 1.6%/mmHg was determined using a linear-fit model. Additionally, an average undershoot of 6.7% +/- 4% and 17.1% +/- 7% was observed in SvO2 and tCBF upon recovery from hypercapnia in six subjects. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 1504-1512; doi: 10.1038/jcbfm.2011.34; published online 20 April 2011