Phlebotomy reverses the hemodynamic consequences of thoracic aortic cross-clamping: relationships between central venous pressure and cerebrospinal fluid pressure.
Phlebotomy reverses the hemodynamic consequences of thoracic aortic cross-clamping: relationships between central venous pressure and cerebrospinal fluid pressure.
复制标题
放血逆转胸主动脉交叉钳夹的血流动力学后果：中心静脉压和脑脊液压力之间的关系。
作者：
W. A. Mutch;I R Thomson;J. Teskey;D. Thiessen;M. Rosenbloom
在用戊巴比妥钠（等电脑电图）麻醉的狗（n = 11）中，作者研究了胸主动脉阻断（AXC）对全身血流动力学和脑脊液压力（CSFP）的影响，同时测量总脑流量（tCBF）和局部（颈椎、胸椎和腰椎）脊髓血流量（SCBF）。评估了放血术（以控制 AXC 的血流动力学后果）对 tCBF 和 SCBF 的影响。在每只动物的四个时间段注射放射性微球：1) 在基线； 2) 应用 AXC； 3）放血后，将近端平均动脉压（MAPp）降低至基线值； 4) 移除 AXC 后 2 分钟（平均 AXC 时间 68 +/- 6 分钟）。应用 AXC 后，MAPp、中心静脉压 (CVP) 和 CSFP 显着增加（分别为 104 +/- 6 至 156 +/- 6 mmHg、3.4 +/- 0.4 至 5.2 +/- 0.7 mmHg 和 3.3 +/- 0.7 至 5.2 +/- 0.8 mmHg），而远端平均主动脉压 (MAPd) 显着降低（98 +/- 6 至 14 +/- 1·1 毫米汞柱）。放血（24 +/- 3 ml.kg-1）显着降低MAPp（至106 +/- 6 mmHg）、CVP（至1.6 +/- 0.6 mmHg）和CSFP（至1.2 +/- 1.1 mmHg）。 CSFP 的变化与 CVP 的变化平行，结果表明 CSFP 的变化取决于心脏前负荷。放血后脊髓灌注压（SCPP；SCPP = MAPd - CSFP）没有变化，因为 MAPd 和 CSFP 均下降。当使用 AXC 使 MAPp 增加 50% 时，tCBF 和宫颈 SCBF 没有变化；这表明自动调节完好无损。（摘要截断为 250 字）
In dogs (n = 11) anesthetized with sodium pentobarbital (to an isoelectric EEG), the authors investigated the influence of thoracic aortic cross-clamping (AXC) on systemic hemodynamics and cerebrospinal fluid pressure (CSFP) with concurrent measurement of total brain flow (tCBF) and regional (cervical, thoracic, and lumbar) spinal cord blood flow (SCBF). The effect of phlebotomy (to control the hemodynamic consequences of AXC) on tCBF and SCBF was assessed. Radioactive microspheres were injected at four time periods in each animal: 1) at baseline; 2) with application of the AXC; 3) after phlebotomy, to reduce the proximal mean arterial pressure (MAPp) to baseline values; and 4) 2 min after removal of the AXC (mean AXC time 68 +/- 6 min). With application of the AXC, the MAPp, central venous pressure (CVP), and CSFP significantly increased (104 +/- 6 to 156 +/- 6 mmHg, 3.4 +/- 0.4 to 5.2 +/- 0.7 mmHg, and 3.3 +/- 0.7 to 5.2 +/- 0.8 mmHg, respectively), while distal mean aortic pressure (MAPd) significantly decreased (98 +/- 6 to 14 +/- 1 1 mmHg). Phlebotomy (24 +/- 3 ml.kg-1) significantly decreased MAPp (to 106 +/- 6 mmHg), CVP (to 1.6 +/- 0.6 mmHg), and CSFP (to 1.2 +/- 1.1 mmHg). The CSFP changed in parallel with the changes in CVP, a result suggesting that the alterations in CSFP depended on cardiac preload. The spinal cord perfusion pressure (SCPP; SCPP = MAPd - CSFP) was unchanged after phlebotomy, since both MAPd and CSFP decreased. The tCBF and cervical SCBF were unchanged when MAPp increased by 50% with application of the AXC; this indicated that autoregulation was intact.(ABSTRACT TRUNCATED AT 250 WORDS)