Efficacy of Gradient Compression Garments in the Hours After Long-Duration Spaceflight

Area of Science:

• Space Medicine
• Physiology
• Aerospace Engineering

Background:

• Long-duration spaceflight leads to high incidence of presyncopal events.
• Over 60% of astronauts experience orthostatic intolerance upon return.
• Current countermeasures are insufficient for mitigating post-flight cardiovascular deconditioning.

Purpose of the Study:

• To evaluate the efficacy of a lower body gradient compression garment (GCG).
• To assess GCG's ability to prevent excessive heart rate increase and blood pressure decrease during standing post-spaceflight.
• To demonstrate GCG's protective effect against orthostatic intolerance.

Main Methods:

• Eleven astronauts (9 male, 2 female) participated in the study.
• A stand test protocol involved 2 minutes of prone rest followed by 3.5 minutes of standing.
• Tests were conducted preflight and postflight (R+0A, R+0B, R+0C) with and without GCG.

Main Results:

• All astronauts completed the stand test preflight.
• Postflight, GCG use did not alter heart rate or mean arterial pressure responses to standing compared to preflight.
• No significant hypotension was observed in astronauts tested with GCG.

Conclusions:

• Gradient compression garments (GCG) effectively prevent tachycardia during standing post-spaceflight.
• GCG protects against blood pressure decrease during short standing tests after spaceflight.
• GCG represents a promising countermeasure for mitigating orthostatic intolerance in astronauts.