Greenfield J C, Rembert J C, Tindall G T
Stroke. 1984 Jan-Feb;15(1):76-9. doi: 10.1161/01.str.15.1.76.
Measurements of cerebral spinal fluid pressure, arterial pressure, and internal carotid artery blood flow were obtained in a series of patients during a Valsalva maneuver. During straining (phase II), an 11% reduction in mean arterial pressure was associated with a 21% decrease in internal carotid flow from control values; and following release (phase IV), the 19% increase in mean arterial pressure produced a 22% increase in internal carotid artery flow. Perfusion pressure computed as the mean arterial pressure minus cerebral spinal fluid pressure and internal carotid artery blood flow were used to calculate an index of cerebral vascular resistance. The data indicate that a modest but significant decrease in vascular resistance occurred during phases II and III followed by return to control levels during phase IV. These changes in vascular resistance were not rapid enough or of sufficient magnitude to maintain constant cerebral perfusion during the Valsalva maneuver.
在一系列患者进行瓦尔萨尔瓦动作期间，测量了脑脊液压力、动脉压和颈内动脉血流。在用力阶段（第二阶段），平均动脉压降低11%，颈内血流较对照值减少21%；而在放松后（第四阶段），平均动脉压升高19%，颈内动脉血流增加22%。用平均动脉压减去脑脊液压力计算灌注压，并结合颈内动脉血流来计算脑血管阻力指数。数据表明，在第二和第三阶段，血管阻力出现适度但显著的降低，随后在第四阶段恢复到对照水平。这些血管阻力的变化不够迅速，幅度也不够大，无法在瓦尔萨尔瓦动作期间维持恒定的脑灌注。
