摘要
目的探讨21天头低位(HDT)卧床对人体立位应激下心血管反应的影响,以及比较下体负压(LBNP)和头高位倾斜(HUT)两种立位应激下心血管反应的差异。方法6名受试者在21天HDT前、后分别进行LBNP(-4.00kPa/3min、-6.67kPa/3min及-9.33kPa/3min)和HUT试验(30°/3min、45°/3min、60°/3min及75°/3min),以比较两种检测方法的血压(BP)和心率(HR)的变化情况。结果与LBNP(或HUT)前相比:①LBNP(HUT)时HR显著增加(P<0.01),SBP显著降低(P<0.05);卧床后相应的变化量增加。②LBNP时DBP降低(卧床后达显著,P<0.05);而HUT时DBP增加(卧床后达显著,P<0.05)。③LBNP时MAP均显著降低(P<0.05);而HUT时在卧床前无变化(P>0.05),在卧床后显著增加(P<0.05)。结论LBNP和HUT引起的CVS反应并不相同。笔者认为,HUT更能促进心血管系统对立位应激的调节作用。
Objective To investigate the effect of 21 days head down tilt (HDT) bed rest (BR) on cardiovascular response to lower body negative pressure (LBNP) and head up tilt (HUT), and the difference between cardiovascular responses to LBNP and HUT. Methods Six healthy male volunteers served as subjects. They underwent LBNP (-4.00 kPa/3 min, -6.67 kPa/3 min, -9.33 kPa/3min) and HUT tests (30/3 min, 45/3 min, 60/3 min and 75/3 min) before and after 21 days HDT bed rest. Blood pressure (BP) and heart rate (HR) during LBNP and HUT were compared. Results Compared with baseline values: HR increased significantly(P<0.01), whereas SBP decreased significantly (P<0.05) during LBNP(or HUT); the corresponding change of HR and SBP became more significant after 21 days HUT bed rest. DBP showed tendency of decrease before bed rest, and decreased significantly (P<0.05) after that during LBNP; whereas showed tendency of increase before bed rest (P>0.05), but increased significantly (P<0.05) after that during HUT. MAP decreased both before and after bed rest(P<0.05) during LBNP, while MAP remained unchange during HUT before bed rest and increased significantly after that (P<0.05). Conclusions The cardiovascular responses to LBNP and HUT are not identical. It is suggested that HUT can better reflect the ability of cardiovascular adjustment to orthostatic stress.
出处
《中华航空航天医学杂志》
CSCD
1999年第1期10-13,共4页
Chinese Journal of Aerospace Medicine
关键词
头低位卧床
下体负压
头高位倾斜
血压
模拟失重
Head down tilt bed restLower body negative pressureHead up tiltBlood pressureHeart rateSimulated weightlessness