模拟低氧暴露对飞行员脑血流灌注的影响

Effect of simulated hypoxic exposure on cerebral blood perfusion of pilots

目的 观察模拟低氧环境下飞行员脑血流灌注特点,为低氧环境下飞行员脑功能鉴定提供生理依据. 方法 35名男性健康飞行员先后接受常压常氧、氧浓度为14.5％的常压低氧暴露,采用动脉自旋标记（arterial spin labeling,ASL）技术检查受试者低氧暴露前后的脑血流灌注,比较两者之间的差异. 结果 低氧暴露后,飞行员的脉搏为（63.97±10.43）次/min,与暴露前（71.46±10.63）次/min相比明显下降（t=4.969,P＜0.01）.低氧暴露后,飞行员的血氧饱和度为（92.46±3.64）％,与暴露前（96.31±1.23）％相比明显下降（t=6.437,P＜0.01）.ASL结果显示双侧颞上回、双侧颞中回、左侧颞下回、右侧枕中回、右侧枕下回、双侧舌回、右侧梭状回、右侧楔叶及小脑部分脑区的血流灌注较前减少（P＜0.05）,未发现血流灌注增加脑区. 结论 低氧暴露后飞行员脑血流灌注均比暴露前明显减少,集中在颞叶及枕叶.运用ASL技术观察低氧暴露后飞行员脑血流灌注变化具有潜在应用价值.

Objective To provide physiological basis of cerebral function identification of pilots in hypoxic environment by observing the pilots＇ cerebral blood perfusion characteristics before and after hypoxic exposure.Methods Thirty-five healthy male pilots were subjected to normal and hypoxic exposure that the oxygen concentration was 14.5%.We inspected the cerebral blood perfusion by arterial spin labeling technology and compared the differences between the two states.Results After hypoxic exposure,the pulse was （63.97± 10.43） beats/min （t=4.969,P〈0.01）,it was lower than before which was （71.46±10.63） beats/min.The oxygen saturation was （92.46±3.64）%,it was lower than before which was （96.31±1.23）% （t=6.437,P〈0.01）.Arterial spin labeling （ASL） in pilots after hypoxic exposure showed lower cerebral blood flow （CBF） values prominently in the following regions：the bilateral superior temporal gyrus,the bilateral middle temporal gyrus,the left inferior temporal gyrus,the right middle occipital gyrus,the right inferior occipital gyrus,the bilateral lingual gyrus,the right fusiform gyrus,the right cuneus and cerebellum （P〈0.05）.Conclusions The cerebral blood perfusion after hypoxic exposure is decreased mainly in the temporal and occipital lobe for the right side,and arterial spin-labeling technique can monitor CBF changes of the pilots in hypoxic exposure.