下身负压下人体心血管系统的代偿功能(英文)  

Compensation of human cardiovascular system with negative pressure of the lower body

作　　者：韩文强[1] 胡文东[1] 马瑞山[2] 

机构地区：[1]解放军第四军医大学航空航天医学系航空航天医学工程研究室,陕西省西安市710032 [2]解放军第四军医大学航空航天医学系航空航天生理学教研室,陕西省西安市710032

出　　处：《中国临床康复》2004年第33期7590-7591,共2页Chinese Journal of Clinical Rehabilitation

摘　　要：背景:下体负压是模拟重力-惯性力场对人体循环功能影响的有效研究方法之一,在一定程度上可模拟正加速度对人体的影响。目的:探讨坐位下身负压暴露时人体心血管系统的代偿功能的变化,为高G值致空中意识丧失(G-LOC)的预防和监控提供生理学参数。设计:随机自身对照实验研究。地点和对象:实验地点在本系脑功能实验室,实验对象为15名健康自愿者青年男性,均系本校大学二年级学员。干预:采用坐位下身负压舱,每名被试者均要受到-4.00kPa、-6.67kPa下身负压的作用。主要观察指标:分别测试负压前、下身负压暴露于-4.00kPa,-6.67kPa的0.5,1,2,3,4,5min和卸压后1,3,5min的血压、心率及主观症状和客观体征等。在-4.00kPa下身负压作用时,收缩压与舒张压与负压前对照差别无显著性意义;心率在下身负压作用3,4,5min时,显著增快(P<0.05)。结果:在-6.67kPa下身负压作用时,心率在负压作用各时间点与负压作用前比较均显著增快(P<0.01);收缩压与负压前对照无明显改变,舒张压显著升高(P<0.05)。结论:坐位下身负压造成血液在下肢积聚,大脑供血量减少,心血管系统通过加强代偿功能,使大部分被试未发生晕厥前症状。随着下身负压值的进一步增大和作用时间的延长,机体出现失代偿现象,导致出现晕厥前症状。BACKGROUND:Lower body negative pressure(LBNP) is one of the effective methods to simulate the influence of gravito-inertial force on human circulation.It can simulate the effects of positive accelerate on human body to a certain extent. OBJECTIVE:To explore the changes of compensation of cardiovascular system with lower body negative pressure in upright seated position(U-LBNP).To provide physiological parameters for the prevention and monitoring of G-induced loss of conciousness(G-LOC). DESIGN: Randomized self-controlled trial. SETTING and PARTICIPANTS:Setting: the Laboratory of Brain Function in the Department of Aerospace of the Fourth Military Medical University of Chinese PLA.Participants: Fifteen voluntary healthy young men were chosen who were the students of Grade Two in this university.INTERVENTIONS: U-LBNP -4.00 kPa and -6.67 kPa were acted on every participant by using U-LBNP cabin.MAIN OUTCOME MEASURES:Heart rate(HR),blood pressure(BP), subjective symptom,objective physical sign,etc.were measured before LBNP,LBNP under -4.00 kPa and -6.67 kPa in 0.5,1,2,3,4,5 minutes and after recovery in 1,3,5 minutes.RESULTS:There was no significant difference in diastolic pressure and systolic pressure before and under -4.00 kPa.U-LBNP under -4.00 kPa in 3,4 and 5 minutes,HR speeded up(0.028 1,P< 0.05) and there were no significant changes comparing BP with the control level.Under -6.67 kPa U-LBNP,HR increased significantly at each time point during U-LBNP comparing with that before U-LBNP(0.000 7,P< 0.01);diastolic pressure increased significantly(0.019 7,P< 0.05),but there were no significant changes in systolic pressure comparing with that before U-LBNP. CONCLUSION:LBNP can cause blood accumulation in lower body and blood supply decrease in brain.Meanwhile, the cardiovascular compensation enhances,which does not cause the presyncopal symptoms(PSS) in most of participants.With the increase in LBNP and the prolongation of time,the organism shows a decompensational phenomenon,which causes the PSS.The physiological d

关 键 词：下身负庄 血压 心率 意识丧失 

分 类 号：R54[医药卫生—心血管疾病]