论文部分内容阅读
目的 观察 2 1d头低位卧床期间脑底动脉血流动力学的变化。 方法 6名健康男性志愿者 ,年龄 ( 2 4.8± 6 .1)岁 ,进行了 2 1d头低位 ( HDT- 6°)卧床试验。HDT前、HDT第 10 d及卧床结束时进行了 3次立位耐力检查。HDT前 (坐位 )、HDT开始时 ( D0 )、第 1、3、7、10、2 1d用经颅超声多普勒 ( TCD)测量了双侧大脑前、中、后动脉的血流动力学指标。 结果 卧床第 10 d和卧床结束时 ,受试者立位耐力比卧床前降低 ( P<0 .0 5 )。卧床期间 ,受试者右侧大脑中动脉的收缩期峰值血流速度vs 和平均血流速度 vm 较卧床前 ( pre- HDT)及卧床开始时降低 ,左侧大脑中动脉 vs在卧床开始时较卧床前增加 ,卧床第 3d又较开始时降低。在卧床前 ,大脑中动脉右左两侧流速差 BVD和右左两侧非对称指数 AI的均数分别为 7.0 cm/ s和 13.74% ,在卧床期间 BVD和 AI均数降为负值 ,较卧床前时降低 ( P<0 .0 5或 P<0 .0 1)。大脑中动脉的其余指标 (含脉动指数和阻力指数等 )、大脑前和后动脉的各指标变化不显著。 结论 2 1d头低位卧床使立位耐力、双侧大脑中动脉的 vs 和右侧大脑中动脉的 vm 降低 ;HDT卧床期间 ,大脑中动脉血流速度降低和不对称变化 ,可能与立位耐力降低有关。
Objective To observe the hemodynamic changes of cerebral artery in 21d head-down bed rest. Methods Six healthy male volunteers, age (2 4.8 ± 6. 1 years), were enrolled in a 21-day HDT-6 ° bed rest. HDT on the 10th day before HDT and bed rest at the end of 3 times stand endurance test. The hemodynamics of the anterior, middle and posterior arteries of the bilateral brains were measured by transcranial Doppler (TCD) before HDT (sitting), at the beginning of HDT (D0), and on days 1,3,7,10,21d index. Results On the 10th day and the end of the bed rest, the subjects’ standing endurance was lower than that before bed-ridden (P <0.05). During bed rest, the subjects’ right middle cerebral artery systolic peak blood flow vs and mean blood flow vm were lower than pre-HDR and ambulation at the beginning of bed rest. The left middle cerebral artery vs vs Increased bedridden, bedridden 3d and lower than the beginning. Before bed rest, the mean velocities of BVD and right asymmetric index AI in the right and left middle cerebral arteries were 7.0 cm / s and 13.74%, respectively. During the ambulation period, the mean BVD and AI decreased to negative values during bed rest, (P <0.05 or P <0.01). The remaining indicators of the middle cerebral artery (including pulse index and resistance index, etc.), before and after the cerebral artery changes in each index was not significant. Conclusion In the first day of low bed rest, the standing endurance, the vs of the bilateral middle cerebral arteries and the vm of the right middle cerebral artery were decreased. The velocity and asymmetry of the middle cerebral artery blood flow during the HDT bed rest may be related to the decrease of standing stamina related.