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| Individual Susceptibility to Post-Space-Flight Orthostatic Intolerance |
| DSO 496 |
| Principal Investigator: Janice M. Yelle, M.S.; Michael G. Ziegler, M.D.; Peggy A. Whitson, Ph.D. |
| Overview |
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Researchers think that postflight orthostatic hypotension occurs in some, but not all, astronauts because of (1) preflight, gender-related differences in autonomic regulation of arterial pressure, and (2) space-flight-induced changes in autonomic function, which precipitate the condition in predisposed individuals. This DSO tests this hypothesis by examining preflight and postflight differences in susceptible and nonsusceptible astronauts. Significant alteration of cardiovascular function after space flight is well documented. One of the most important changes negatively affecting flight operations and crew safety is the postflight loss of orthostatic tolerance. Symptoms include difficulty walking independently, lightheadedness or fainting, and impaired ability to climb out of the Shuttle after landing. Recent evidence indicates that postflight autonomic dysfunction contributes to orthostatic intolerance. Susceptibility to postflight orthostatic intolerance is highly individual. Some astronauts experience very little effect, others have severe symptoms, and women are more often affected than men. The goal of the proposed studies is to clarify mechanisms responsible for these problems in order to customize countermeasures that prevent them. Three crew members will participate in this study, only before and after the flight. |
Editorial/Technical Comments: ShuttlePresskit
