Dahl A, Russell D, Rootwelt K, Nyberg-Hansen R, Kerty E
Department of Neurology, Rikshospitalet, The National Hospital, University of Oslo, Norway.
Stroke. 1995 Dec;26(12):2302-6. doi: 10.1161/01.str.26.12.2302.
To improve the assessment of cerebral vasoreactivity using acetazolamide (ACZ), we studied the time course of the response and the relationship between dose, response, and serum concentration.
Blood flow velocities were measured with the use of transcranial Doppler ultrasonography in one of the middle cerebral arteries of 48 healthy subjects after the intravenous administration of 1 to 1.6 g ACZ. In 34 subjects (group 1), velocities were measured every second minute to detect the maximum middle cerebral artery velocity increase. We also measured regional cerebral blood flow using single-photon emission computed tomography in 27 of the subjects in group 1 before and approximately 15 to 20 minutes after the ACZ injection. The serum concentration of ACZ was measured in 15 subjects. In the remaining 14 subjects (group 2), middle cerebral artery velocity measurements were made 10, 25, 30, and 45 minutes after ACZ administration to obtain information regarding the late time course of the response.
In group 1 the plateau phase of the velocity response was reached 8 to 15 minutes after ACZ administration. A large range of velocity increase was observed, and a significant correlation was found between the maximum velocity increase and the dose and serum concentration of ACZ. In group 2 subjects, maximum velocities were maintained 30 minutes after the injection, but after 45 minutes velocities had decreased to 68% of their highest level. No significant relationship was found between dose or serum concentration of ACZ and the regional cerebral blood flow increase. The velocity increase after ACZ was similar in both older and younger subjects.
This study shows that cerebral vasoreactivity is best assessed 10 to 30 minutes after ACZ administration and that the dose should probably exceed 15 mg/kg if a maximum vasodilatory response in the cerebral circulation is to be obtained.
为了改进使用乙酰唑胺（ACZ）对脑血管反应性的评估，我们研究了反应的时间进程以及剂量、反应和血清浓度之间的关系。
对48名健康受试者静脉注射1至1.6 g ACZ后，使用经颅多普勒超声在其中一支大脑中动脉测量血流速度。在34名受试者（第1组）中，每隔两分钟测量一次速度，以检测大脑中动脉速度的最大增加值。我们还在第1组的27名受试者中，在注射ACZ前及注射后约15至20分钟使用单光子发射计算机断层扫描测量局部脑血流量。在15名受试者中测量ACZ的血清浓度。在其余14名受试者（第2组）中，在注射ACZ后10、25、30和45分钟测量大脑中动脉速度，以获取有关反应后期时间进程的信息。
在第1组中，ACZ给药后8至15分钟达到速度反应的平台期。观察到速度增加范围很大，并且在最大速度增加与ACZ的剂量和血清浓度之间发现显著相关性。在第2组受试者中，注射后30分钟保持最大速度，但45分钟后速度降至最高水平的68%。未发现ACZ的剂量或血清浓度与局部脑血流量增加之间存在显著关系。ACZ给药后的速度增加在老年和年轻受试者中相似。
本研究表明，在ACZ给药后10至30分钟评估脑血管反应性最佳，如果要在脑循环中获得最大血管舒张反应，剂量可能应超过15 mg/kg。
