Differences in cerebral blood flow between alpha-stat and pH-stat management are eliminated during periods of decreased systemic flow and pressure. A study during cardiopulmonary bypass in rabbits.
Differences in cerebral blood flow between alpha-stat and pH-stat management are eliminated during periods of decreased systemic flow and pressure. A study during cardiopulmonary bypass in rabbits.
复制标题
在全身血流和压力降低期间，α-stat 和 pH-stat 管理之间的脑血流量差异被消除。
作者：
B. Hindman;N. Funatsu;J. Harrington;J. Cutkomp;T. Miller;M. M. Todd;J. Tinker
先前的报告表明，α-stat 和 pH-stat 管理之间的脑血流量 (CBF) 对改变旁路（全身）流速的反应可能有所不同。为了比较血气管理对 CBF 对改变的全身流量和压力的反应的影响，15 只新西兰白兔，用芬太尼和地西泮麻醉，在 25 摄氏度下进行非搏动心肺转流术。一组动物 (n = 8) 被随机分配至 alpha-stat 血气管理，在 37 摄氏度下测量时，维持动脉二氧化碳张力 (PaCO2) 约 40 mmHg。第二组 (n = 7) 采用 pH 静态技术进行管理，根据动物的实际温度进行校正后，将 PaCO2 维持在约 40 mmHg。以 100 ml.kg-1.min-1 的流速启动旁路，大约 20 分钟后，进行控制血流动力学和 CBF 测量（放射性微球）。此后，旁路流速以15分钟间隔随机改变为50、70和100ml.kg-1.min-1。在改变旁路流量的每个周期结束时重复 CBF 和血流动力学测量。各组在 pHa 和 PaCO2 方面存在显着差异。在任何测量点的旁路流量、平均动脉压（MAP）、中心静脉压、温度、血细胞比容、动脉氧分压（PaCO2）或旁路持续时间方面，各组之间没有显着差异。随着旁路流量的减少，MAP 显着下降，从约 80 毫米汞柱降至约 65 毫米汞柱 (P = 0.0001)。在整个旁路流量范围内，CBF随着旁路流量的减小而减小（P = 0.001），并且区域间和组间的变化程度相当。（摘要截断为250字）
Prior reports suggest cerebral blood flow (CBF) responses to changing bypass (systemic) flow rates may differ between alpha-stat and pH-stat management. To compare the effect of blood gas management upon CBF responses to changing systemic flow and pressure, 15 New Zealand White rabbits, anesthetized with fentanyl and diazepam, underwent nonpulsatile cardiopulmonary bypass at 25 degrees C. One group of animals (n = 8) was randomized to alpha-stat blood gas management that maintained arterial carbon dioxide tension (PaCO2) approximately 40 mmHg when measured at 37 degrees C. A second group (n = 7) was managed with pH-stat technique, maintaining PaCO2 approximately 40 mmHg when corrected to the animal's actual temperature. Bypass was initiated at a flow rate of 100 ml.kg-1.min-1 and, after approximately 20 min, control hemodynamic and CBF measurements (radioactive microspheres) were made. Thereafter, bypass flow rate was changed in random order at 15-min intervals to 50, 70, and 100 ml.kg-1.min-1. CBF and hemodynamic measurements were repeated at the end of each period of altered bypass flow. Groups differed significantly with respect to both pHa and PaCO2. There were no significant differences between groups with respect to bypass flow rate, mean arterial pressure (MAP), central venous pressure, temperature, hematocrit, arterial oxygen tension (PaCO2), or bypass duration at any measurement point. MAP decreased significantly, from approximately 80 to approximately 65 mmHg with decreasing bypass flow (P = 0.0001). Over the entire range of bypass flows, CBF decreased with decreasing bypass flow (P = 0.001), and the degree of change was equivalent among regions and between groups.(ABSTRACT TRUNCATED AT 250 WORDS)