飞行时间对飞行员动态脑血流动力学的影响

Effects of flying time on the cerebral hemodynamics of pilots

目的 探讨飞行时间对飞行员动态脑血流动力学特征的影响. 方法 现役飞行员99名,飞行机种包括歼击机和直升机.按飞行时间分为两组:飞行时间≤600 h组,42名,年龄(27.9±4.3)岁；飞行时间＞600 h组,57名,年龄(32.5±5.9)岁.对照组为69名健康志愿者,年龄(26.6±4.5)岁.采用多普勒超声技术分别观察受试者大脑前、中、后动脉,椎动脉及基底动脉的收缩期峰值血流速度(systolic velocity,Vs)、舒张末期血流速度(diastolic velocity,Vd)、平均血流速度(mean velocity,Vm)及搏动指数(pulsatility index,PI).以年龄为协变量,对数据进行协方差分析.结果 与对照组相比,飞行时间≤600 h组基底动脉和右侧大脑后动脉PI明显增加(t=2.27、2.11,P＜0.05),而飞行时间＞600 h组右侧大脑前动脉PI明显降低(t=2.07,P＜0.05).与飞行时间≤600 h组同侧比,飞行时间＞600 h组左侧大脑后动脉的Vs和右侧大脑后动脉的Vd明显增加(t=2.00、2.07,P＜0.05)；而右侧大脑后动脉的PI明显降低(t=2.51,P＜0.05).其他血流动力学参数未见明显的统计学改变. 结论 长期进行飞行训练能提高飞行员脑血管调节能力,促进血管内皮功能发挥,提高血管顺应性.

Objective To investigate the effects of flying time on the cerebral hemodynamics of pilots.Methods Ninety-nine active pilots,including fighter and helicopter pilots,were divided into flying time ≤600 h group (aged 27.9±4.3 yr,n=42) and flying time ＞600 h group (aged 32.5±5.9 yr,n=57).Sixty-nine healthy volunteers (age 26.6±4.5 yr) were selected as the control group.The systolic velocity (Vs),diastolic velocity (Vd),mean velocity(Vm) and pulsatility index (PI) of anterior cerebral artery,vertebral artery and the basilar artery of subjects were measured by tanscranial Doppler sonography technique.The data were processed by the covariance analysis with age covariate.Results Compared with the control group,the flying time ≤600 h group showed significantly increased PI of basilar artery and right posterior cerebral artery (t =2.27,2.11,P＜0.05),while flying time ＞600 h group had significantly lower PI of right anterior cerebral artery (t=2.07,P＜0.05).Compared with those of flying time ≤600 h group,Vs of left posterior cerebral artery and Vd of right middle cerebral artery of flying time ＞ 600 h group increased significantly (t=2.00,2.07,P＜0.05),and PI of right postcrior cerebral artery was significantly low (t=2.51,P＜0.05).Other hemodynamic parameters had no statistically changes.Conclusions The durable flight training has certain effects on improving pilot's regulation,vasodilatation and complaisance of cerebral arteries.