Gorman D F, Browning D M
Undersea Biomed Res. 1986 Sep;13(3):317-35.
Compression regimens effect redistribution of entrapped cerebral arterial gas emboli by reducing embolus length and/or by increasing local perfusion pressure. Embolus length is related to embolus volume and vessel diameter. It has been assumed without evidence that cerebral arterial gas emboli induce local vasoparalysis and hence that the relevant vessel diameter will not be affected by the treatment regimen. This study tested that assumption. Infusion of gas microbubbles into the femoral artery of upright rabbits caused significant but transient hypertension, respiratory depression, cardiac bradyarrythmia, inhibition of cerebrovascular autoregulation to blood pressure changes, and cerebral arterial gas embolism, with entrapment of long emboli in arterioles of 50-200 micron diameter. Cerebral arterioles constricted and dilated appropriately with sequential changes in ventilation gas mixture both before and after gas embolism. The study demonstrated that cerebral arterial gas emboli did not necessarily inhibit cerebrovascular reactivity and that the effect a compression regimen has on cerebral arteriole diameter should be included in any assessment of its efficacy.
加压方案通过缩短栓子长度和/或增加局部灌注压力来影响被困在脑动脉中的气体栓子的重新分布。栓子长度与栓子体积和血管直径有关。在没有证据的情况下，人们一直认为脑动脉气体栓子会导致局部血管麻痹，因此相关血管直径不会受到治疗方案的影响。本研究对这一假设进行了验证。向直立兔子的股动脉内注入气体微泡会导致显著但短暂的高血压、呼吸抑制、心脏心动过缓、脑血管对血压变化的自动调节功能受到抑制以及脑动脉气体栓塞，长栓子被困在直径为50 - 200微米的小动脉中。在气体栓塞前后，随着通气气体混合物的顺序变化，脑小动脉会相应地收缩和扩张。该研究表明，脑动脉气体栓子不一定会抑制脑血管反应性，并且在评估加压方案的疗效时，应考虑其对脑小动脉直径的影响。
