Space flight fluid shifts measured by leg volume changes
Abstract
Signs and symptoms secondary to fluid shifts in weightlessness are common physiologic effects noted in the manned spaceflight program. The extent and nature of fluid shifts associated with spaceflight were studied in six adult males by determination of leg volume changes. Four major conclusions were drawn. First, a leg volume loss of 12.7 percent or 2.2 liters occurs during spaceflight. Secondly, the fluid shift that accounts for the volume loss occurs rapidly on Mission Day 1 with it being essentially complete by 11 to 13 hours into the mission. Thirdly, the regional origin of the shift and leg volume change shows variation in the absolute volume and percentage volume change. Leg volume segments of the thigh or upper leg have a greater absolute volume and percentage change as compared to the lower leg. And finally, postflight, the return of fluid to the lower extremities occurs rapidly with the majority of volume return complete within 1.5 hours of landing. At 1 week postflight there is a residual leg volume decriment of 4.3 percent that is probably due to tissue loss secondary to atrophic deconditioning and weight loss.
Degree
Ph.D.
Advisors
Ismail, Purdue University.
Subject Area
Anatomy & physiology|Animals
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