SUP／HUT反复体位改变对心血管反应和脑血氧的影响研究

摘要

Repeated body position change test is an important way to test or research the orthostatic tolerance of astronauts. In order to find a Shorter Interval of Supine/Head⁃Up Tilt ( SUP/HUT ) mode that can improve body orthostatic tolerance, 15 healthy subjects were exposed to SUP/HUT (0°, 2 min→+75°, 2min;repeated 10 times)mode position change on a tilt bed. The features of physiological changes of cardiovascular effects and cerebral oxygenation were investigated. As com⁃pared with the first HUT, SBP, DBP and MAP were all significantly elevated at the tenth HUT(∗P<0. 05) in both supine and head⁃up tilt phase;However, O2Hb and tHb were all significantly ele⁃vated at the fifth HUT and the tenth HUT (∗P<0 . 05 ) in the head⁃up tilt phase; In Squat Stand Test (SST), SBP, DBP and MAP in 20s and 30s were all significantly elevated at post⁃SST(∗P<0. 05) as compare with the pre⁃SST. The results showed that SUP/HUT(0°,2 min→+75°,2min;repeated 10 times) as a Shorter Interval mode can effectively improve the body orthostatic tolerance. These findings may promote the research on human cardiovascular regulation and be used to improve the training efficiency of astronauts.%反复体位改变是航天员立位耐力的测试与研究的重要方法。为找到平卧位／头高位（ SUP／HUT）反复体位改变对立位耐力有显著提高的相对较短时长，15名健康志愿者在旋转床上进行SUP／HUT（0°，2 min→＋75°，2 min；重复10次）模式的实验，研究该模式反复体位改变对心血管功能和脑血氧的影响。研究发现：第10次倾斜平卧位和头高位SBP、DBP、MAP和TPR均分别显著高于第1次倾斜时的平卧位和头高位（∗P＜0�05）；第5、10次倾斜时头高位的O2 Hb和tHb显著高于第1次（∗P＜0�05）；实验前后SST结果表明，SBP、DBP和MAP在实验后蹲位和站立的20 s和30 s内的值明显高于实验前（∗P＜0�05）。此研究表明（0°，2 min→＋75°，2 min；重复10次）实验可显著提高人体立位耐力，是相对较短时长的、能够提高立位耐力的SUP／HUT模式，可用于提高航天员训练效率。