Melçhior F M, Thullier P H, Lejeune D, Kerguélen M, Srinivasan R S
Laboratoire de Médecine Aérospatiale, Centre d'Essais en Vol, Brétigny S/Orge, France.
Aviat Space Environ Med. 1996 Dec;67(12):1161-5.
Astronauts returning from spaceflight are affected by reduced orthostatic tolerance resulting from exposure to weightlessness. There are some countermeasures currently in use to improve cardiovascular performance of returning astronauts, while there are others that are being tested in flight and in ground-based investigations. This paper presents a study on the use of elastic compression stockings to reduce leg blood capacity (LBC) which is believed to be one of the determinants of orthostatic tolerance.
The data are from 6 healthy men with a mean age of 36 +/- 5 (SE) yr. Assessment of the effectiveness of stockings in improving orthostatic tolerance is based on a presyncopal-limited lower body negative pressure (LBNP) test, consisting of successive 3 min exposures to negative pressures of -20 hPa (-15 mmHg), -40 hPa (-30 mmHg), and decrements in steps of 10 hPa (7.5 mmHg) from then on until termination of the test.
Results show an increase in the maximal level of LBNP tolerated (88 hPa or 66 mmHg for control vs. 108 hPa or 81 mmHg for stockings; p = 0.018) as well as in the cumulative stress index (CSI) (1122 hPa-min or 842 mmHg-min for control vs. 1734 hPa-min or 1300 mmHg-min for stockings; p = 0.029).
The improvement of LBNP tolerance with elastic compression stockings coupled with their ease of use support the need for further experimental studies for evaluating their potential as a countermeasure for astronauts after return from spaceflight.
从太空飞行返回的宇航员会受到失重导致的直立耐力降低的影响。目前有一些对策用于改善返回地球的宇航员的心血管功能，同时也有其他一些对策正在进行飞行测试和地面研究。本文介绍了一项关于使用弹性压缩袜来减少腿部血容量（LBC）的研究，腿部血容量被认为是直立耐力的决定因素之一。
数据来自6名平均年龄为36±5（标准误）岁的健康男性。基于晕厥前受限的下体负压（LBNP）测试评估袜子在改善直立耐力方面的有效性，该测试包括连续3分钟暴露于-20 hPa（-15 mmHg）、-40 hPa（-30 mmHg）的负压，然后以10 hPa（7.5 mmHg）的步长递减，直至测试结束。
结果显示，耐受的LBNP最大水平有所提高（对照组为88 hPa或66 mmHg，穿袜子组为108 hPa或81 mmHg；p = 0.018），累积应激指数（CSI）也有所提高（对照组为1122 hPa·min或842 mmHg·min，穿袜子组为1734 hPa·min或1300 mmHg·min；p = 0.029）。
弹性压缩袜对LBNP耐受性的改善及其易用性，支持进一步开展实验研究以评估其作为宇航员返回太空后对策的潜力。
