Sequential Changes of Cerebral Blood Flow after Acetazolamide Acetazolamide Loading in Hemodynamic Cerebral Ischemia: Relationship to Cerebral Oxygen Metabolism

本研究旨在探讨乙酰唑胺负荷后脑血流量（CBF）与脑氧代谢（cmo_2）的序贯变化关系。研究对象包括30例内颈动脉、大脑中动脉或椎基底动脉严重狭窄或闭塞的患者。静息状态和静脉给药1 g乙酰唑胺后6、16、30分钟，采用[^<15>]H_2 O灌注法和正电子发射断层扫描法测定局部脑血流。在CBF研究之前，采用[^<15>]O_2吸入法测量脑区域氧提取分数（OEF）。基于CBF和OEF计算区域cmoro_2。良好反应型（乙酰唑胺加载后6分钟CBF增幅大于20%）、矛盾反应型（乙酰唑胺加载后6分钟CBF下降）和不良反应型（乙酰唑胺加载后6分钟CBF增幅小于20%）分别在39个、11个和10个区域被发现。响应类型较好的区域OEF正常，cmoro_2正常。矛盾反应区OEF增加。反应类型较差的区域GEF正常，cmoro_2降低。综上所述，笔者认为乙酰唑胺负荷后连续测量脑血流量（CBF）可以了解血流动力学缺血患者的局部脑氧代谢状态，应在给药后早期测量CBF，以准确检测血流灌注。

The aim of this study was to clarify relationship between sequential changes of cerebral blood flow (CBF) after acetazolamide loading and cerebral oxygen metabolism (CMRO_2). The subjects consisted of 30 patients with severe stenosis or occlusion of the internal carotid or middle cerebral or vertebro-basilar artery. Regional CBF was measured at the resting state and at 6, 16 and 30 minutes after the intravenous administration of 1 g acetazolamide using the [^<15>O]H_2 O bolus-injection method and positron emission tomography. Prior to CBF study, regional cerebral oxygen extraction fraction (OEF) was measured using the [^<15>O]O_2 inhalation method. Regional CMRO_2 was calculated based on CBF and OEF. Good response type (CBF increase rate more than 20% at 6 minutes after acetazolamide loading), paradoxical response type (decrease of CBF at 6 minutes after acetazolamide loading) and poor response type (CBF increase rate less than 20% at 6 minutes after acetazolamide loading) were identified in 39, 11 and 10 areas, respectively. Areas with good response type showed normal OEF and normal CMRO_2. Areas with paradoxical response type showed increased OEF. Areas with poor response type showed normal GEF and decreased CMRO_2. In view of these findings, the author concludes that sequential measurement of cerebral blood flow (CBF) after acetazolamide loading enables to know regional cerebral oxygen metabolic state in patients with hemodynamic ischemia, and CBF should be measured early after the administration of acetazolamide to accurately detect misery perfusion.