Stenger Michael B, Brown Angela K, Lee Stuart M C, Locke James P, Platts Steven H
Integrated Science and Engineering Group, NASA/Johnson Space Center, 1290 Hercules Drive, Houston, TX 77058, USA.
Aviat Space Environ Med. 2010 Sep;81(9):883-7. doi: 10.3357/asem.2781.2010.
Post-spaceflight orthostatic intolerance affects approximately 30% of short-duration and 80% of long-duration crewmembers. While the current NASA antigravity suit is effective during Space Shuttle re-entry, it is not designed to be worn postflight and has several drawbacks. The purpose of this study was to evaluate the use of commercially available, thigh-high, gradient compression garments to prevent post-spaceflight orthostatic intolerance.
Before spaceflight, five male Shuttle astronauts were fitted for compression garments. Postflight stand time, blood pressure, heart rate, stroke volume, cardiac output, and peripheral resistance during 10-min, 80 degrees head-up tilt test within 4 h of landing in these astronauts were retrospectively compared to a group of nine male astronauts not wearing the compression garments.
On landing day, three of nine non-countermeasure astronauts developed presyncopal symptoms and could not complete the test, while no countermeasure subjects became presyncopal. Compared to the non-countermeasure subjects, the countermeasure subjects had higher systolic blood pressure (116 +/- 3 vs. 134 +/- 2 mmHg), stroke volume (42 +/- 5 vs. 57 +/- 6 ml), and cardiac output (3.1 +/- 0.3 vs. 4.6 +/- 0.4 L). Heart rate was not different between groups.
In this small pilot study, the rate of presyncope in the non-countermeasure group was similar to that reported previously in subjects without a compression garment. In contrast, thigh-high graded compression garments mitigated the symptoms of orthostatic intolerance by improving stroke volume, cardiac output, and systolic blood pressure responses to standing.
太空飞行后体位性不耐受影响约30%的短期飞行和80%的长期飞行机组人员。虽然目前美国国家航空航天局（NASA）的抗重力服在航天飞机重返大气层期间有效，但它并非设计用于飞行后穿着，且存在若干缺点。本研究的目的是评估使用市售的大腿高梯度压力服装预防太空飞行后体位性不耐受的效果。
在太空飞行前，为五名男性航天飞机宇航员配备了压力服装。对这些宇航员着陆后4小时内进行的10分钟、80度头高位倾斜试验期间的飞行后站立时间、血压、心率、每搏输出量、心输出量和外周阻力，与一组九名未穿着压力服装的男性宇航员进行回顾性比较。
着陆当天，九名未采取对策的宇航员中有三名出现晕厥前症状，无法完成试验，而采取对策的受试者未出现晕厥前症状。与未采取对策的受试者相比，采取对策的受试者收缩压更高（116±3 vs. 134±2 mmHg）、每搏输出量更高（42±5 vs. 57±6 ml）、心输出量更高（3.1±0.3 vs. 4.6±0.4 L）。两组之间心率无差异。
在这项小型试点研究中，未采取对策组的晕厥前期发生率与先前报道的未穿压力服装受试者的发生率相似。相比之下，大腿高梯度压力服装通过改善每搏输出量、心输出量以及对站立的收缩压反应，减轻了体位性不耐受的症状。
