Miller J D, Ledingham I M, Jennett W B
J Neurol Neurosurg Psychiatry. 1970 Dec;33(6):745-55. doi: 10.1136/jnnp.33.6.745.
Increased intracranial pressure was induced in anaesthetized dogs by application of liquid nitrogen to the dura mater. Intracranial pressure and cerebral blood flow were measured, together with arterial blood pressure and arterial and cerebral venous blood gases.Carbon dioxide was administered intermittently to test the responsiveness of the cerebral circulation, and hyperbaric oxygen was delivered at intervals in a walk-in hyperbaric chamber, pressurized to two atmospheres absolute.Hyperbaric oxygen caused a 30% reduction of intracranial pressure and a 19% reduction of cerebral blood flow in the absence of changes in arterial PCO(2) or blood pressure, but only as long as administration of carbon dioxide caused an increase in both intracranial pressure and cerebral blood flow. When carbon dioxide failed to influence intracranial pressure or cerebral blood flow then hyperbaric oxygen had no effect. This unresponsive state was reached at high levels of intracranial pressure.
通过向硬脑膜施加液氮在麻醉的狗身上诱导颅内压升高。测量颅内压和脑血流量，同时测量动脉血压以及动脉和脑静脉血气。间歇性给予二氧化碳以测试脑循环的反应性，并在步入式高压舱中间歇性输送高压氧，将舱内压力升至两个绝对大气压。在动脉血二氧化碳分压（PCO₂）或血压无变化的情况下，高压氧使颅内压降低30%，脑血流量降低19%，但前提是给予二氧化碳会使颅内压和脑血流量均增加。当二氧化碳未能影响颅内压或脑血流量时，高压氧则无作用。这种无反应状态在颅内压处于高水平时出现。
