Oertel Matthias F, Scharbrodt Wolfram, Wachter Dorothee, Stein Marco, Schmidinger Andrea, Böker Dieter-Karsten
Department of Neurosurgery, Universitätsklinikum Giessen-Marburg, Giessen, Germany.
J Clin Neurosci. 2008 Jun;15(6):630-6. doi: 10.1016/j.jocn.2007.04.003. Epub 2008 Apr 2.
After subarachnoid hemorrhage (SAH) the detection of hemodynamically significant vasospasm is frequently difficult, especially in comatose patients. Most clinicians use transcranial Doppler sonography (TCD) to detect increasing mean blood flow velocities in the basal arteries as markers of cerebral vasospasm, without accounting for the effects of sedation and variations in blood pressure or pCO(2). This study was conducted to test the hypothesis that the arteriovenous difference of oxygen (avDO(2); in terms of % volume) could also be useful for the evaluation of vasospasm. A total of 22 SAH patients (M : F = 1 : 1.75, age 58+/-10 years, median Hunt and Hess grade 4) were prospectively enrolled. All patients were sedated with continuous doses of midazolam/fentanyl and/or propofol. TCD studies and avDO(2) measurements were conducted at the same time or in close succession. The blood flow velocity of the middle cerebral artery was recorded. A cranial CT scan was conducted if the avDO(2) increased by at least 0.8%. Overall, 82 measurements were recorded in 22 patients between days 1 and 13 after SAH. TCD mean flow velocities increased as expected. In contrast, avDO(2) decreased until post-hemorrhage day 4 before it increased again. Overall, after SAH, avDO(2) was significantly lower than in normal individuals. Cerebral infarction occurred primarily in patients with a maximal change of avDO(2) of more than 1%. TCD velocities alone are poor indicators of the severity of vasospasm. In contrast, daily avDO(2) seems to be a more robust parameter. However, collection of additional metabolic information is warranted.
蛛网膜下腔出血（SAH）后，检测具有血流动力学意义的血管痉挛通常很困难，尤其是在昏迷患者中。大多数临床医生使用经颅多普勒超声（TCD）检测基底动脉平均血流速度增加，以此作为脑血管痉挛的标志，而未考虑镇静作用以及血压或pCO₂的变化。本研究旨在检验以下假设：动静脉氧差（avDO₂；以容积百分比计）也可用于评估血管痉挛。前瞻性纳入了22例SAH患者（男∶女 = 1∶1.75，年龄58±10岁，Hunt和Hess分级中位数为4级）。所有患者均持续静脉输注咪达唑仑/芬太尼和/或丙泊酚进行镇静。同时或相继进行TCD研究和avDO₂测量。记录大脑中动脉的血流速度。若avDO₂至少增加0.8%，则进行头颅CT扫描。总体而言，在SAH后第1天至第13天期间，对22例患者进行了82次测量。TCD平均血流速度如预期增加。相比之下，avDO₂在出血后第4天之前下降，之后再次上升。总体而言，SAH后avDO₂显著低于正常个体。脑梗死主要发生在avDO₂最大变化超过1%的患者中。单独的TCD速度并非血管痉挛严重程度的良好指标。相比之下，每日avDO₂似乎是一个更可靠的参数。然而，仍有必要收集更多代谢信息。
