脑血流量由动脉压决定，而非体外循环流量。

Cerebral blood flow is determined by arterial pressure and not cardiopulmonary bypass flow rate.

作者信息

Schwartz A E, Sandhu A A, Kaplon R J, Young W L, Jonassen A E, Adams D C, Edwards N M, Sistino J J, Kwiatkowski P, Michler R E

机构信息

Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.

出版信息

Ann Thorac Surg. 1995 Jul;60(1):165-9; discussion 169-70.

PMID:7598581

Abstract

BACKGROUND

During cardiopulmonary bypass, global hypoperfusion of the brain has been shown to result in ischemic insult and subsequent neurologic injury. Furthermore, outcome after focal cerebral ischemia depends on collateral circulation, which is determined by the parameters of global perfusion. We therefore measured cerebral blood flow during independent manipulations of arterial blood pressure and pump flow rate to determine which of these hemodynamic parameters regulates cerebral perfusion during cardiopulmonary bypass.

METHODS

Seven anesthesized baboons were placed on cardiopulmonary bypass and cooled to 28 degrees C. Pump flow rate and arterial blood pressure were altered in varied sequence to each of four conditions: (1) full flow (2.23 +/- 0.06 L.min-1.m-2, mean +/- standard deviation) at high pressure (61 +/- 2 mm Hg), (2) full flow (2.23 +/- 0.06 L.min-1.m-2) at low pressure (24 +/- 3 mm Hg), (3) low flow (0.75 L.min-1.m-2) at high pressure (62 +/- 2 mm Hg), and (4) low flow (0.75 L.min-1.m-2 at low pressure (23 +/- 3 mm Hg). During each of these hemodynamic conditions cerebral blood flow was measured by washout of intracarotid xenon.

RESULTS

Cerebral blood flow was greater at high blood pressure than at low pressure during cardiopulmonary bypass both at low flow (34 +/- 8.3 versus 14.1 +/- 3.7 mL.min-1 x 100 g-1) and full flow (27.6 +/- 9.9 versus 16.8 +/- 3.7 mL.min-1 x 100 g-1) (p < 0.01). At comparable mean arterial blood pressures alteration of pump flow rate produced no changes in cerebral blood flow.

CONCLUSIONS

These results indicate that cerebral blood flow during moderately hypothermic cardiopulmonary bypass is regulated by arterial blood pressure and not pump flow rate.

摘要

背景

在体外循环期间，已表明大脑的整体灌注不足会导致缺血性损伤及随后的神经损伤。此外，局灶性脑缺血后的结果取决于侧支循环，而侧支循环由整体灌注参数决定。因此，我们在独立调节动脉血压和泵流量时测量脑血流量，以确定这些血流动力学参数中的哪一个在体外循环期间调节脑灌注。

方法

将七只麻醉的狒狒置于体外循环并冷却至28摄氏度。泵流量和动脉血压以不同顺序改变至四种状态：（1）高压（61±2 mmHg）下的全流量（2.23±0.06 L·min⁻¹·m⁻²，平均值±标准差），（2）低压（24±3 mmHg）下的全流量（2.23±0.06 L·min⁻¹·m⁻²），（3）高压（62±2 mmHg）下的低流量（0.75 L·min⁻¹·m⁻²），以及（4）低压（23±3 mmHg）下的低流量（0.75 L·min⁻¹·m⁻²）。在每种血流动力学状态下，通过颈内动脉氙洗脱法测量脑血流量。