倒立位暴露后头高位倾斜联合-9.33kPa下体负压对心血管功能的影响  

Cardiovascular responses to head-up tilt with lower body negative pres sure (-9.33 kPa) following exposure to head-down tilt

作　　者：姚永杰[1] 孙誉洋[1] 孙喜庆[1] 韦应波[1] 杨长斌[1] 陈健[1] 姜卫[1] 

机构地区：[1]第四军医大学航空航天医学系航空航天生物动力学教研室,陕西西安710033

出　　处：《第四军医大学学报》2003年第2期156-159,共4页Journal of the Fourth Military Medical University

摘　　要：目的 :观察倒立位暴露后头高位倾斜联合 - 9 33kPa的下体负压对心血管功能的影响 ,进一步探讨下体负压倾斜床模拟航空推拉效应的效果 .方法 :8名受试者在下体负压倾斜床上进行“直立位→倒立位→直立位 +下体负压 (-9 33kPa)致晕厥 /晕厥前状态”的模拟推拉效应试验及“单纯直立位 +下体负压 (- 9 33kPa)致晕厥 /晕厥前状态”的对照试验 ,用阻抗法测量试验过程中心率 (HR)、血压 (BP)、基础阻抗 (Z0 )、每搏心输出量 (SV)、心输出量 (CO)及总外周阻力(TPR)等心血管功能指标的变化 .结果 :模拟推拉效应试验的下体负压耐受时间显著比对照试验的低 (P <0 0 5 ) .模拟推拉效应试验时 ,倒立位与直立位对照相比较 ,受试者HR、Z0 显著降低 (P <0 0 1) ,SV、SI、CO、CI显著升高 (P <0 0 1) ;在直立位 +下体负压暴露时 ,心血管功能指标的变化与对照试验时的变化类似 ,即HR、TPR较HUT值显著增高 (P <0 0 5orP <0 0 1) ,SV、SI、CO、SI较HUT值显著降低 (P <0 0 5orP <0 0 1) .在对照试验时 ,SBP显著降低 (P <0 0 1) .在模拟推拉效应试验时 ,在直立位 +下体负压暴露开始 1min内 ,DBP、MBP较HUT值显著增高 (P <0 0 5orP <0 0 1) .结论 :倒立位后 ,再直立 +LBNP暴露的耐受时间显著低于单纯直立 +LBNP暴露的?AIM : To observe cardiovascular responses t o head-up tilt (HUT) with lower body negative pressure (LBNP) following exposure t o head-down tilt (HDT) and to evaluate the effect of push-pull effect (PPE) simu lated by LBNP tilt-table. METHODS : A special LBNP tilt-table w as used to simulate push-pull effect. Eight healthy male adults were studied in two experiments: One was simulated PPE test and the other was control test. The changes of heart rate (HR), blood pressure (BP), basic impedance (Z 0), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI) and tota l peripheral resistance (TPR) were monitored by electrical impedance instrument during the experiments. RESULTS: In the simulated PPE e xperiment, average standing time before the subjects showed presyncopal symptoms was significantly lower than that of the control test (P<0 05), and HR, and Z 0 during HDT were significantly lowered than the value of HUT (+1G z) position (P<0 01), while SV, SI, CO an d CI were increased significantly (P<0 01). In the PPE experiment as well as in control experiment, HR and TPR in '+1G z with LBNP' position were significantly higher (P<0 05 or P <0 01), while SV, SI, CO and CI were significantly lower than t hose of HUT position (P<0 05 or P<0 01). In control experiment, SBP of '+1G z with LBNP' was lowered signif icantly than HUT value(P<0 01). In the simulated PPE experiment,DBP and MBP during the first min of '+1G z with LBNP' were signif icantly higher than HUT value (P<0 05 or P<0 01). CONCLUSION: After HDT, HUT with LBNP shor tens the tolerance time before the appearance of presyncopal symptoms. LBNP tilt -table can be used to simulated push-pull effect.

关 键 词：倒立位 心血管功能 倾斜台试验 推拉模拟 推拉效应 加速度 

分 类 号：R852.21[医药卫生—航空、航天与航海医学]