下体负压与下肢局部加压对模拟推拉动作时脑血流的保护作用研究  

Study of the protective effects of lower body negative pressure strategy and thigh cuff strategy on cerebral blood flow during simulated push pull maneuver

作　　者：邢长洋 高原 王馨佩 刘云楠 张佳欣 王辰 张星 李嘉 常婷 张舒 刘勇 袁丽君 高峰 Xing Changyang;Gao Yuan;Wang Xinpei;Liu Yunnan;Zhang Jiaxin;Wang Chen;Zhang Xing;Li Jia;Chang Ting;Zhang Shu;Liu Yong;Yuan Lijun;Gao Feng(School of Aerospace Medicine,Air Force Medical University,Xi′an 710032,China;Tangdu Hospital,Air Force Medical University,Xi′an 710038,China)

机构地区：[1]空军军医大学航空航天医学系,西安710032 [2]空军军医大学第二附属医院,西安710038

出　　处：《中华航空航天医学杂志》2021年第1期1-6,共6页Chinese Journal of Aerospace Medicine

基　　金：基础加强计划重点基础研究项目(2019-JCJQ-ZD-196-00);国家博士后创新人才支持计划(BX20180377);陕西省创新人才推进计划-科技创新团队(2020-TD-038);空军军医大学雏鹰计划;空军军医大学第二附属医院科技创新发展基金(2019JSYJ001)。

摘　　要：目的对比下体负压(lower body negative pressure,LBNP)策略与下肢局部加压策略对模拟推拉动作时脑血流的保护作用。方法研究采用重复交叉设计。15名健康成年男性为受试者。所有受试者均经历无干预模拟推拉动作测试(对照轮)、带LBNP的模拟推拉动作测试(LBNP轮)、带下肢局部加压的模拟推拉动作测试。将受试者随机分为3组(A、B、C组),每组5人;A组的试验顺序为对照轮?LBNP轮?下肢局部加压轮,B组的试验顺序为LBNP轮?下肢局部加压轮?对照轮,C组的试验顺序为下肢局部加压轮?对照轮?LBNP轮。通过旋转床"直立位?头低位?直立位"模拟推拉动作。对照轮进行单纯模拟推拉动作;LBNP轮于-Gz阶段施加-40?mmHg(1 mmHg=0.133 kP)的LBNP,+Gz阶段释放;下肢局部加压轮于-Gz阶段在双侧大腿上段加压200 mmHg,持续至+Gz阶段。记录模拟推拉动作过程中受试者脑血流动力学变化。结果模拟推拉动作-Gz向+Gz转换后,对照轮受试者平均脑血流速度(mean cerebral blood flow velocity,CBFVm)减低了0.7~17.3 cm/s[ΔCBFVm=(-7.5±4.5)cm/s],脑水平平均动脉压(mean arterial pressure at the level of middle cerebral artery,MAPMCA)降低了42~76 mmHg[ΔMAPMCA=(-61.0±10.0)mmHg]。而受试者LBNP轮的平均脑血流速度变化量为-2.4~10.2 cm/s,其均值不仅没有减低反而升高了(3.3±4.1)cm/s;MAPMCA下降幅度为23~50 mmHg[ΔMAPMCA=(-41.0±11.0)mmHg],显著小于对照轮(P<0.05)。受试者下肢局部加压轮的CBFVm变化幅度为-7.9~1.4 cm/s[ΔCBFVm=(-3.0±4.2)cm/s],MAPMCA下降幅度为37~59 mmHg[ΔMAPMCA=(-47.0±13.0)mmHg],二者均显著小于对照轮(P<0.05)。受试者LBNP轮与下肢局部加压轮的CBFVm变化幅度差异有统计学意义(P<0.05),两轮间MAPMCA变化差异无统计学意义。结论LBNP及下肢局部加压策略均对受试者模拟推拉动作时的脑血流具有保护作用;以CBFVm为标准,LBNP策略的保护效果较好;二者均主要通过提高舒张期脑血流发挥保�Objective To compare the protective effects of cerebral blood flow during simulated push pull maneuver(PPM)between lower body negative pressure(LBNP)strategy and thigh cuff(TC)strategy.Methods It was a repeated cross-over design study.Fifteen healthy young male subjects were recruited.All subjects underwent the control bout(simulated PPM without any intervention),PPM with LBNP bout,and PPM with TC bout.Such position changes as"upright to head down tilt to upright"were performed by tilting table to simulate PPM.The control bout underwent normal PPM.LBNP of-40 mmHg(1 mmHg=0.133 kP)was applied prior to and during-Gz stress and released at the subsequent transition to+Gz stress in LBNP bout.TC of+200 mmHg was applied at bilateral upper thighs prior to and during simulated PPM.Beat-to-beat cerebral and systemic hemodynamics of the subjects were continuously recorded.Results During the rapid-Gz to+Gz transition,the mean cerebral blood flow velocity(CBFVm)was decreased by 0.7-17.3 cm/s[ΔCBFVm=(-7.5±4.5)cm/s],and the mean arterial pressure at the level of middle cerebral artery(MAPMCA)was decreased by 42-76 mmHg[ΔMAPMCA=(-61.0±10.0)mmHg]in control bout.However,the change of CBFVm was-2.4-10.2 cm/s in LBNP bout,whose average value was increased(3.3±4.1)cm/s rather than decreased.The drop of MAPMCA was 23-50 mmHg[ΔMAPMCA=(-41.0±11.0)mmHg],which was significantly reduced than that in control bout(P<0.05).The change of CBFVm in TC bout was-7.9-1.4 cm/s[ΔCBFVm=(-3.0±4.2)cm/s],and the decrease ofΔMAPMCA was 37-59 mmHg[ΔMAPMCA=(-47.0±13.0)mmHg],both of which were significantly smaller than that in control bout(P<0.05).There was significant difference inΔCBFVm between LBNP and TC bouts(P<0.05),while no significant difference was found inΔMAPMCA.Conclusions Both the LBNP and TC strategies can protect the cerebral blood flow during simulated PPM.LBNP strategy showed better improvement of CBFVm than TC.Both strategies demonstrated protective effect by increasing diastolic cerebral blood flow.

关 键 词：推拉动作 脑血流 下体负压 

分 类 号：R85[医药卫生—航空、航天与航海医学]