Macko R F, Ameriso S F, Akmal M, Paganini-Hill A, Mohler J G, Massry S G, Meiselman H J, Fisher M
Department of Neurology, University of Southern California School of Medicine, Los Angeles.
Stroke. 1993 Jul;24(7):1025-8. doi: 10.1161/01.str.24.7.1025.
Transcranial Doppler blood flow velocities are inversely related to age and hematocrit, but the relative importance of age, oxygenation, and hemorheological factors has not previously been examined. We evaluated the relative contributions of these factors to middle cerebral artery blood flow velocity in adults with chronic renal failure, a population subject to significant fluctuations in hematologic profile.
Twenty-six subjects were studied, with arterial shunt blood sampled at the time of transcranial Doppler before dialysis. Twenty subjects from the original cohort were studied twice to examine the effects of intraindividual changes in blood oxygenation and rheology on Doppler velocities.
Age (r = -.61, P < .001), high-shear viscosity (r = -.46, P < .02), and arterial oxygen content (r = -.44, P < .05) were all inversely related to middle cerebral artery blood flow velocity. Age was the strongest velocity predictor, accounting for 37% of variance by simple regression analysis. Intraindividual change in arterial oxygen content explained most (54%) of the middle cerebral artery blood flow velocity variation between studies (r = -.74, P < .001). Multiple regression analysis showed that inclusion of additional variables could not account for more velocity variation than change in arterial oxygen content alone.
In this population, age and arterial oxygen content were the most important determinants of interindividual middle cerebral artery blood flow velocity variance and intraindividual middle cerebral artery blood flow velocity variation, respectively.
经颅多普勒血流速度与年龄及血细胞比容呈负相关，但年龄、氧合作用及血液流变学因素的相对重要性此前尚未得到研究。我们评估了这些因素对慢性肾衰竭成年患者大脑中动脉血流速度的相对贡献，这一人群的血液学指标存在显著波动。
对26名受试者进行了研究，在透析前经颅多普勒检查时采集动脉分流血液样本。对原始队列中的20名受试者进行了两次研究，以检验个体血液氧合作用和流变学变化对多普勒速度的影响。
年龄（r = -0.61，P < 0.001）、高切变粘度（r = -0.46，P < 0.02）和动脉血氧含量（r = -0.44，P < 0.05）均与大脑中动脉血流速度呈负相关。年龄是最强的速度预测因子，通过简单回归分析占方差的37%。研究之间，动脉血氧含量的个体内变化解释了大部分（54%）大脑中动脉血流速度变化（r = -0.74，P < 0.001）。多元回归分析表明，纳入其他变量并不能比单独的动脉血氧含量变化解释更多的速度变化。
在这一人群中，年龄和动脉血氧含量分别是个体间大脑中动脉血流速度差异及个体内大脑中动脉血流速度变化的最重要决定因素。
